< draft-ietf-ipp-implementers-guide-00.txt   draft-ietf-ipp-implementers-guide-01.txt >
INTERNET-DRAFT INTERNET-DRAFT
draft-ietf-ipp-implementers-guide-00.txt draft-ietf-ipp-implementers-guide-01.txt
T. Hastings T. Hastings
Xerox Corporation Xerox Corporation
C. Manros C. Manros
Xerox Corporation Xerox Corporation
November 16, 1998 February 12, 1999
Internet Printing Protocol/1.0: Implementer's Guide Internet Printing Protocol/1.0: Implementer's Guide
Copyright (C) The Internet Society (date). All Rights Reserved. Copyright (C) The Internet Society (1999). All Rights Reserved.
Status of this Memo Status of this Memo
This document is an Internet-Draft. Internet-Drafts are working This document is an Internet-Draft and is in full conformance with all
provisions of Section 10 of [RFC2026]. Internet-Drafts are working
documents of the Internet Engineering Task Force (IETF), its areas, and documents of the Internet Engineering Task Force (IETF), its areas, and
its working groups. Note that other groups may also distribute working its working groups. Note that other groups may also distribute working
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Abstract Abstract
This document is one of a set of documents, which together describe all This document is one of a set of documents, which together describe all
aspects of a new Internet Printing Protocol (IPP). IPP is an aspects of a new Internet Printing Protocol (IPP). IPP is an
application level protocol that can be used for distributed printing application level protocol that can be used for distributed printing
using Internet tools and technologies. This document contains using Internet tools and technologies. This document contains
information that supplements the IPP Model and Semantics [IPP-MOD] and information that supplements the IPP Model and Semantics [IPP-MOD] and
the IPP Transport and Encoding [IPP-PRO] documents. It is intended to the IPP Transport and Encoding [IPP-PRO] documents. It is intended to
help implementers understand IPP/1.0 and some of the considerations that help implementers understand IPP/1.0 and some of the considerations that
may assist them in the design of their client and/or IPP object may assist them in the design of their client and/or IPP object
implementations. For example, a typical order of processing requests is implementations. For example, a typical order of processing requests is
given, including error checking. Motivation for some of the given, including error checking. Motivation for some of the
specification decisions is also included. specification decisions is also included.
Expires May 16, 1999 Expires August 12, 1999
The full set of IPP documents includes: The full set of IPP documents includes:
Design Goals for an Internet Printing Protocol [IPP-REQ] Design Goals for an Internet Printing Protocol [IPP-REQ]
Rationale for the Structure and Model and Protocol for the Internet Rationale for the Structure and Model and Protocol for the Internet
Printing Protocol [IPP-RAT] Printing Protocol [IPP-RAT]
Internet Printing Protocol/1.0: Model and Semantics [IPP-MOD] Internet Printing Protocol/1.0: Model and Semantics [IPP-MOD]
Internet Printing Protocol/1.0: Encoding and Transport [IPP-PRO] Internet Printing Protocol/1.0: Encoding and Transport [IPP-PRO]
Mapping between LPD and IPP Protocols [IPP LPD] Mapping between LPD and IPP Protocols [IPP LPD]
The document, "Design Goals for an Internet Printing Protocol", takes a The document, "Design Goals for an Internet Printing Protocol", takes a
skipping to change at page 3, line 5 skipping to change at page 3, line 5
The document, "Internet Printing Protocol/1.0: Encoding and Transport", The document, "Internet Printing Protocol/1.0: Encoding and Transport",
is a formal mapping of the abstract operations and attributes defined in is a formal mapping of the abstract operations and attributes defined in
the model document onto HTTP/1.1. It also defines the encoding rules the model document onto HTTP/1.1. It also defines the encoding rules
for a new Internet media type called "application/ipp". for a new Internet media type called "application/ipp".
The document, "Mapping between LPD and IPP Protocols", gives some advice The document, "Mapping between LPD and IPP Protocols", gives some advice
to implementers of gateways between IPP and LPD (Line Printer Daemon) to implementers of gateways between IPP and LPD (Line Printer Daemon)
implementations. implementations.
Expires May 16, 1999 Expires August 12, 1999
TABLE OF CONTENTS TABLE OF CONTENTS
1 Introduction......................................................5 1 Introduction.......................................................5
1.1 Conformance language...........................................5 1.1 Conformance language............................................5
1.2 Other terminology...............................................5
1.2 Other terminology..............................................6 2 Model and Semantics................................................5
2 Model and Semantics...............................................6 2.1 Summary of Operation Attributes.................................5
2.2 Suggested Operation Processing Steps for IPP Objects (Issue 1.21)9
2.2.1 Suggested Operation Processing Steps for all Operations....10
2.2.1.1 Validate version number................................10
2.2.1.2 Validate operation identifier..........................11
2.2.1.3 Validate the request identifier........................11
2.2.1.4 Validate attribute group and attribute presence and order
11
2.2.1.5 Validate the values of the REQUIRED Operation attributes18
2.2.1.6 Validate the values of the OPTIONAL Operation attributes22
2.2.2 Suggested Additional Processing Steps for Operations that
Create/Validate Jobs and Add Documents...........................24
2.2.2.1 Default "ipp-attribute-fidelity" if not supplied.......24
2.2.2.2 Check that the Printer object is accepting jobs........24
2.2.2.3 Validate the values of the Job Template attributes.....24
2.2.3 Algorithm for job validation...............................25
2.2.3.1 Check for conflicting Job Template attributes values...30
2.2.3.2 Decide whether to REJECT the request...................30
2.2.3.3 For the Validate-Job operation, RETURN one of the success
status codes....................................................31
2.2.3.4 Create the Job object with attributes to support.......31
2.2.3.5 Return one of the success status codes.................33
2.2.3.6 Accept appended Document Content.......................33
2.2.3.7 Scheduling and Starting to Process the Job.............33
2.2.3.8 Completing the Job.....................................33
2.2.3.9 Destroying the Job after completion....................34
2.2.3.10 Interaction with "ipp-attribute-fidelity"..............34
2.3 Status codes returned by operation (Issue 1.50)................34
2.3.1 Printer Operations.........................................34
2.3.1.1 Print-Job..............................................34
2.3.1.2 Print-URI..............................................36
2.3.1.3 Validate-Job...........................................37
2.3.1.4 Create-Job.............................................37
2.3.1.5 Get-Printer-Attributes.................................37
2.3.1.6 Get-Jobs...............................................38
2.3.2 Job Operations.............................................38
2.3.2.1 Send-Document..........................................38
2.3.2.2 Send-URI...............................................39
2.3.2.3 Cancel-Job.............................................39
2.3.2.4 Get-Job-Attributes.....................................40
2.4 Validate-Job...................................................41
2.5 Case Sensitivity in URIs (issue 1.6)...........................41
2.6 Character Sets, natural languages, and internationalization....41
2.6.1 Character set code conversion support (Issue 1.5)..........41
2.6.2 What charset to return when an unsupported charset is
requested (Issue 1.19)?..........................................42
2.1 Suggested Operation Processing Steps for IPP Objects...........6 Expires August 12, 1999
2.6.3 Natural Language Override (NLO) (Issue 1.45)...............43
2.7 The "queued-job-count" Printer Description attribute...........44
2.7.1 Why is "queued-job-count" RECOMMENDED (Issue 1.14)?........44
2.7.2 Is "queued-job-count" a good measure of how busy a printer is
(Issue 1.15)?....................................................45
2.8 Sending empty attribute groups (Issue 1.16)....................45
2.9 Returning unsupported attributes in Get-Xxxx responses (Issue
1.18)..............................................................45
2.10Returning job-state in Print-Job response (Issue 1.30).........46
2.11Flow controlling the data portion of a Print-Job request (Issue
1.22)..............................................................46
2.12Multi-valued attributes (Issue 1.31)...........................47
2.13Querying jobs with IPP that were submitted using other job
submission protocols (Issue 1.32)..................................47
2.14The 'none' value for empty sets (Issue 1.37)...................48
2.15Get-Jobs, my-jobs='true', and 'requesting-user-name' (Issue 1.39)?
48
2.16The "multiple-document-handling" Job Template attribute and
support of multiple document jobs..................................48
2.1.1 Suggested Operation Processing Steps for all Operations.....7 3 Encoding and Transport............................................49
2.1.1.1 Validate version number.................................7 3.1 General Headers................................................50
3.2 Request Headers...............................................50
3.3 Response Headers...............................................52
3.4 Entity Headers................................................52
3.5 Optional support for HTTP/1.0..................................53
3.6 HTTP/1.1 Chunking..............................................53
3.6.1 Disabling IPP Server Response Chunking.....................53
3.6.2 Warning About the Support of Chunked Requests..............54
2.1.1.2 Validate operation identifier...........................7 4 References........................................................54
2.1.1.3 Validate the request identifier.........................7 4.1 Authors. Address...............................................55
2.1.1.4 Validate attribute group and attribute presence and order8 5 Notices.................................Error! Bookmark not defined.
2.1.1.5 Validate the values of the REQUIRED Operation attributes15 6 Change History....................................................56
2.1.1.6 Validate the values of the OPTIONAL Operation attributes18 6.1 Changes to produce the February 12, 1999 version from the January
8, 1999 version:...................................................57
6.2 Changes to produce the January 8, 1999 version from the December
6, 1998 version:...................................................57
6.3 Changes to produce the December 6, 1998 version from the November
16, 1998 version:..................................................57
2.1.2 Suggested Additional Processing Steps for Operations that Expires August 12, 1999
Create/Validate Jobs and Add Documents...........................20
2.1.2.1 Default "ipp-attribute-fidelity" if not supplied.......20 1 Introduction
2.1.2.2 Check that the Printer object is accepting jobs........20 This document contains information that supplements the IPP Model and
Semantics [IPP-MOD] and the IPP Transport and Encoding [IPP-PRO]
documents. As such this information is not part of the formal
specifications. Instead information is presented to help implementers
understand the specification, including some of the motivation for
decisions taken by the committee in developing the specification. Some
of the implementation considerations are intended to help implementers
design their client and/or IPP object implementations. If there are any
contradictions between this document and [IPP-MOD] or [IPP-PRO], those
documents take precedence over this document.
2.1.2.3 Validate the values of the Job Template attributes.....20 1.1 Conformance language
2.1.2.4 Check for conflicting Job Template attributes values...25 Usually, this document does not contain the terminology MUST, MUST NOT,
MAY, NEED NOT, SHOULD, SHOULD NOT, REQUIRED, and OPTIONAL. However,
when those terms do appear in this document, their intent is to repeat
what the [IPP-MOD] and [IPP-PRO] documents require and allow, rather
than specifying additional conformance requirements. These terms are
defined in section 13 on conformance terminology in [IPP-MOD], most of
which is taken from RFC 2119 [RFC2119].
2.1.2.5 Decide whether to REJECT the request...................25 Implementers should read section 13 in [IPP-MOD] in order to understand
these capitalized words. The words MUST, MUST NOT, and REQUIRED
indicate what implementations are required to support in a client or IPP
object in order to be conformant to [IPP-MOD] and [IPP-PRO]. MAY, NEED
NOT, and OPTIONAL indicate was is merely allowed as an implementer
option. The verbs SHOULD and SHOULD NOT indicate suggested behavior,
but which is not required or disallowed, respectively, in order to
conform to the specification.
2.1.2.6 For the Validate-Job operation, RETURN one of the success 1.2 Other terminology
status codes....................................................26
2.1.2.7 Create the Job object with attributes to support.......26 The term "sender" refers to the client that sends a request or an IPP
object that returns a response. The term "receiver" refers to the IPP
object that receives a request and to a client that receives a response.
2.1.2.8 Return one of the success status codes.................28 2 Model and Semantics
2.1.2.9 Accept appended Document Content.......................28 This section discusses various aspects of IPP/1.0 Model and Semantics
[IPP-MOD].
2.1.2.10Scheduling and Starting to Process the Job.............28 2.1 Summary of Operation Attributes
2.1.2.11Completing the Job.....................................28 Legend for the following table:
2.1.2.12Destroying the Job after completion....................29 Expires August 12, 1999
R indicates a REQUIRED operation or attribute for an implementation
to support
Expires May 16, 1999 O indicates an OPTIONAL operation or attribute for an
2.1.2.13Interaction with "ipp-attribute-fidelity"..............29 implementation to support
2.2 Status codes returned by operation............................29 Table 1. Summary of operation attributes
2.2.1 Printer Operations.........................................29 Job Operations
2.2.1.1 Print-Job..............................................29 Requests Respo
nses
2.2.1.2 Print-URI..............................................31 Operation Send- Send- Cancel Get- All
Attributes Documen URI -Job Job- Opera
t (O) Attribu tions
(O) tes
2.2.1.3 Validate-Job...........................................31 Operation parameters--REQUIRED to be supplied by the sender
2.2.1.4 Create-Job.............................................31 operation-id R R R R
2.2.1.5 Get-Printer-Attributes.................................32 status-code R
2.2.1.6 Get-Jobs...............................................32 request-id R R R R R
2.2.2 Job Operations.............................................33 version-number R R R R R
2.2.2.1 Send-Document..........................................33 Operation attributes.REQUIRED to be supplied by the sender
2.2.2.2 Send-URI...............................................34 attributes- R R R R R
charset
2.2.2.3 Cancel-Job.............................................34 attributes- R R R R R
natural-language
2.2.2.4 Get-Job-Attributes.....................................35 document-uri R
2.3 Validate-Job..................................................36 job-id* R R R R
2.4 Case Sensitivity in URIs......................................36 job-uri* R R R R
2.5 Natural Language Override (NLO)...............................36 last-document R R
2.6 The "queued-job-count" Printer Description attribute..........38 printer-uri R R R R
2.6.1 Why is "queued-job-count" RECOMMENDED?.....................38 Operation attributes.RECOMMENDED to be supplied by the
sender
2.6.2 Is "queued-job-count" a good measure of how busy a printer is? job-name
38
2.7 Sending empty attribute groups................................38 requesting-user- R R R R
name
2.8 Returning unsupported attributes in Get-Xxxx responses........38 Expires August 12, 1999
Printer Operations
2.9 Returning job-state in Print-Job response.....................38 Requests Respon
ses
2.10 Multi-valued attributes.....................................39 Operation Print- Pri Crea Get- Get- All
Attributes Job, nt- te- Printe Jobs Operat
Valida URI Job r- ions
te-Job (O) (O) Attrib
utes
3 Encoding and Transport...........................................40 Operation attributes.OPTIONAL to be supplied by the sender
3.1 General Headers...............................................41 status-message O
3.2 Request Headers..............................................41 compression O O
Expires May 16, 1999 document-format R R O
3.3 Response Headers..............................................42
3.4 Entity Headers...............................................43 document-name O O
3.5 Optional support for HTTP/1.0.................................44 document-natural- O O
language
3.6 HTTP/1.1 Chunking.............................................44 ipp-attribute- R R R
fidelity
4 References.......................................................45 job-impressions O O O
4.1 Authors' Address..............................................45 job-k-octets O O O
5 Appendix C: Full Copyright Statement.............................46 job-media-sheets O O O
1 Introduction limit R
This document contains information that supplements the IPP Model and message
Semantics [IPP-MOD] and the IPP Transport and Encoding [IPP-PRO]
documents. As such this information is not part of the formal
specifications. Instead information is presented to help implementers
understand the specification, including some of the motivation for
decisions taken by the committee in developing the specification. Some
of the implementation considerations are intended to help implementers
design their client and/or IPP object implementations. If there are any
contradictions between this document and [IPP-MOD] or [IPP-PRO], those
documents take precedence over this document.
1.1 Conformance language my-jobs R
Usually, this document does not contain the terminology MUST, MUST NOT, requested- R R
MAY, NEED NOT, SHOULD, SHOULD NOT, REQUIRED, and OPTIONAL. However, attributes
when those terms do appear in this document, their intent is to repeat
what the [IPP-MOD] and [IPP-PRO] documents require and allow, rather
than specifying additional conformance requirements. These terms are
defined in section 13 on conformance terminology in [IPP-MOD], most of
which is taken from RFC 2119 [RFC2119].
Implementers should read section 13 in [IPP-MOD] in order to understand which-jobs R
these capitalized words. The words MUST, MUST NOT, and REQUIRED
indicate what implementations are required to support in a client or IPP
object in order to be conformant to [IPP-MOD] and [IPP-PRO]. MAY, NEED
NOT, and OPTIONAL indicate was is merely allowed as an implementer
option. The verbs SHOULD and SHOULD NOT indicate suggested behavior,
but which is not required or disallowed, respectively, in order to
conform to the specification.
Expires May 16, 1999 * "job-id" is REQUIRED only if used together with
1.2 Other terminology "printer-uri" to identify the target job; otherwise, "job-
uri" is REQUIRED.
The term "sender" refers to the client that sends a request or an IPP Expires August 12, 1999
object that returns a response. The term "receiver" refers to the IPP
object that receives a request and to a client that receives a response.
2 Model and Semantics Table 2. Summary of operation attributes
This section discusses various aspects of IPP/1.0 Model and Semantics Printer Operations
[IPP-MOD].
2.1 Suggested Operation Processing Steps for IPP Objects Requests Respo
nses
Operation Print- Pri Crea Get- Get- All
Attributes Job, nt- te- Printer- Jobs Opera
Validate URI Job Attribut tions
-Job (O) (O) es
Operation parameters--REQUIRED to be supplied by the sender
operation-id R R R R R
status-code R
request-id R R R R R R
version-number R R R R R R
Operation attributes.REQUIRED to be supplied by the sender
attributes-charset R R R R R R
attributes- R R R R R R
natural-language
document-uri R
job-id*
job-uri*
last-document
printer-uri R R R R R
Operation attributes.RECOMMENDED to be supplied by the sender
job-name R R R
requesting-user- R R R R R
name
Expires August 12, 1999
Job Operations
Requests Respon
ses
Operation Attributes Send- Send- Cance Get- All
Documen URI l-Job Job- Operat
t (O) Attrib ions
(O) utes
Operation attributes.OPTIONAL to be supplied by the sender
status-message O
compression O O
document-format R R
document-name O O
document-natural- O O
language
ipp-attribute-
fidelity
job-impressions
job-k-octets
job-media-sheets
limit
message O
my-jobs
requested-attributes R
which-jobs
* "job-id" is REQUIRED only if used together with "printer-
uri" to identify the target job; otherwise, "job-uri" is
REQUIRED.
2.2 Suggested Operation Processing Steps for IPP Objects (Issue 1.21)
This section suggests the steps and error checks that an IPP object MAY This section suggests the steps and error checks that an IPP object MAY
perform when processing requests and returning responses. An IPP object perform when processing requests and returning responses. An IPP object
MAY perform some or all of the error checks. However, some MAY perform some or all of the error checks. However, some
implementations MAY choose to be more forgiving than the error checks implementations MAY choose to be more forgiving than the error checks
shown here, in order to be able to accept requests from non-conforming shown here, in order to be able to accept requests from non-conforming
clients. Not performing all of these error checks is a so-called clients. Not performing all of these error checks is a so-called
"forgiving" implementation. On the other hand, clients that "forgiving" implementation. On the other hand, clients that
successfully submit requests to IPP objects that do perform all the successfully submit requests to IPP objects that do perform all the
error checks will be more likely to be able to interoperate with other error checks will be more likely to be able to interoperate with other
IPP object implementations. Thus an implementer of an IPP object needs IPP object implementations. Thus an implementer of an IPP object needs
to decide whether to be a "forgiving" or a "strict" implementation. to decide whether to be a "forgiving" or a "strict" implementation.
Therefore, the error status codes returned may differ between Therefore, the error status codes returned may differ between
implementations. Consequentially, client SHOULD NOT expect exactly the implementations. Consequentially, client SHOULD NOT expect exactly the
error code processing described in this section. error code processing described in this section.
When an IPP object receives a request, the IPP object either accepts or When an IPP object receives a request, the IPP object either accepts or
rejects the request. In order to determine whether or not to accept or rejects the request. In order to determine whether or not to accept or
reject the request, the IPP object SHOULD execute the following steps. reject the request, the IPP object SHOULD execute the following steps.
Expires August 12, 1999
The order of the steps may be rearranged and/or combined, including The order of the steps may be rearranged and/or combined, including
making one or multiple passes over the request. making one or multiple passes over the request.
A client MUST supply requests that would pass all of the error checks A client MUST supply requests that would pass all of the error checks
indicated here in order to be a conforming client. Therefore, a client indicated here in order to be a conforming client. Therefore, a client
SHOULD supply requests that are conforming, in order to avoid being SHOULD supply requests that are conforming, in order to avoid being
rejected by some IPP object implementations. rejected by some IPP object implementations and/or risking different
semantics by different implementations of forgiving implementations.
For example, a forgiving implementation that accepts multiple
occurrences of the same attribute, rather than rejecting the request
might use the first occurrences, while another might use the last
occurrence. Thus such a non-conforming client would get different
results from the two forgiving implementations.
In the following, processing continues step by step until a "RETURNS the In the following, processing continues step by step until a "RETURNS the
xxx status code ." statement is encountered. Error returns are xxx status code ." statement is encountered. Error returns are
indicated by the verb: "REJECTS". Since clients have difficulty getting indicated by the verb: "REJECTS". Since clients have difficulty getting
the status code before sending all of the document data in a Print-Job the status code before sending all of the document data in a Print-Job
request, clients SHOULD use the Validate-Job operation before sending request, clients SHOULD use the Validate-Job operation before sending
large documents to be printed, in order to validate whether the IPP large documents to be printed, in order to validate whether the IPP
Printer will accept the job or not. Printer will accept the job or not.
It is assumed that security authentication and authorization has already It is assumed that security authentication and authorization has already
taken place at a lower layer. taken place at a lower layer.
Expires May 16, 1999 2.2.1Suggested Operation Processing Steps for all Operations
2.1.1Suggested Operation Processing Steps for all Operations
This section is intended to apply to all operations. The next section This section is intended to apply to all operations. The next section
contains the additional steps for the Print-Job, Validate-Job, Print- contains the additional steps for the Print-Job, Validate-Job, Print-
URI, Create-Job, Send-Document, and Send-URI operations that create URI, Create-Job, Send-Document, and Send-URI operations that create
jobs, adds documents, and validates jobs. jobs, adds documents, and validates jobs.
2.1.1.1 Validate version number 2.2.1.1 Validate version number
Every request and every response contains the "version-number" Every request and every response contains the "version-number"
attribute. The value of this attribute is the major and minor version attribute. The value of this attribute is the major and minor version
number of the syntax and semantics that the client and IPP object is number of the syntax and semantics that the client and IPP object is
using, respectively. The "version-number" attribute remains in a fixed using, respectively. The "version-number" attribute remains in a fixed
position across all future versions so that all clients and IPP object position across all future versions so that all clients and IPP object
that support future versions can determine which version is being used. that support future versions can determine which version is being used.
The IPP object checks to see if the major version number supplied in the The IPP object checks to see if the major version number supplied in the
request is supported. If not, the Printer object REJECTS the request request is supported. If not, the Printer object REJECTS the request
and RETURNS the 'server-error-version-not-supported' status code in the and RETURNS the 'server-error-version-not-supported' status code in the
response. The IPP object returns in the "version-number" response response. The IPP object returns in the "version-number" response
attribute the major and minor version for the error response. Thus the attribute the major and minor version for the error response. Thus the
client can learn at least one major and minor version that the IPP client can learn at least one major and minor version that the IPP
object supports. The IPP object is encouraged to return the closest object supports. The IPP object is encouraged to return the closest
version number to the one supplied by the client. version number to the one supplied by the client.
The checking of the minor version number is implementation dependent, The checking of the minor version number is implementation dependent,
however if the client supplied minor version is explicitly supported, however if the client supplied minor version is explicitly supported,
the IPP object MUST respond using that identical minor version number. the IPP object MUST respond using that identical minor version number.
If the requested minor version is not supported (the requested minor If the requested minor version is not supported (the requested minor
Expires August 12, 1999
version is either higher or lower) than a supported minor version, the version is either higher or lower) than a supported minor version, the
IPP object SHOULD return the closest supported minor version. IPP object SHOULD return the closest supported minor version.
2.1.1.2 Validate operation identifier 2.2.1.2 Validate operation identifier
The Printer object checks to see if the "operation-id" attribute The Printer object checks to see if the "operation-id" attribute
supplied by the client is supported as indicated in the Printer object's supplied by the client is supported as indicated in the Printer object's
"printer-operations-supported" attribute. If not, the Printer REJECTS "operations-supported" attribute. If not, the Printer REJECTS the
the request and returns the 'server-error-operation-not-supported' request and returns the 'server-error-operation-not-supported' status
status code in the response. code in the response.
2.1.1.3 Validate the request identifier 2.2.1.3 Validate the request identifier
The Printer object SHOULD NOT check to see if the "request-id" attribute The Printer object SHOULD NOT check to see if the "request-id" attribute
supplied by the client is in range: between 1 and 2**31 - 1 (inclusive), supplied by the client is in range: between 1 and 2**31 - 1 (inclusive),
but copies all 32 bits. but copies all 32 bits.
Note: The "version-number", "operation-id", and the "request-id" Note: The "version-number", "operation-id", and the "request-id"
parameters are in fixed octet positions in the IPP/1.0 encoding. The parameters are in fixed octet positions in the IPP/1.0 encoding. The
"version-number" parameter will be the same fixed octet position in all "version-number" parameter will be the same fixed octet position in all
versions of the protocol. These fields are validated before proceeding versions of the protocol. These fields are validated before proceeding
with the rest of the validation. with the rest of the validation.
Expires May 16, 1999 2.2.1.4 Validate attribute group and attribute presence and order
2.1.1.4 Validate attribute group and attribute presence and order
The order of the following validation steps depends on implementation. The order of the following validation steps depends on implementation.
2.1.1.4.1 Validate the presence and order of attribute groups 2.2.1.4.1 Validate the presence and order of attribute groups
Client requests and IPP object responses contain attribute groups that Client requests and IPP object responses contain attribute groups that
Section 3 requires to be present and in a specified order. An IPP Section 3 requires to be present and in a specified order. An IPP
object verifies that the attribute groups are present and in the correct object verifies that the attribute groups are present and in the correct
order in requests supplied by clients (attribute groups without an * in order in requests supplied by clients (attribute groups without an * in
the following tables). the following tables).
If an IPP object receives a request with (1) required attribute groups If an IPP object receives a request with (1) required attribute groups
missing, or (2) the attributes groups are out of order, or (3) the missing, or (2) the attributes groups are out of order, or (3) the
groups are repeated, the IPP object REJECTS the request and RETURNS the groups are repeated, the IPP object REJECTS the request and RETURNS the
skipping to change at page 8, line 34 skipping to change at page 12, line 5
for an attribute group to occur more than once, except in the Get-Jobs for an attribute group to occur more than once, except in the Get-Jobs
response. response.
Since this kind of attribute group error is most likely to be an error Since this kind of attribute group error is most likely to be an error
detected by a client developer rather than by a customer, the IPP object detected by a client developer rather than by a customer, the IPP object
NEED NOT return an indication of which attribute group was in error in NEED NOT return an indication of which attribute group was in error in
either the Unsupported Attributes group or the Status Message. Also, either the Unsupported Attributes group or the Status Message. Also,
the IPP object NEED NOT find all attribute group errors before returning the IPP object NEED NOT find all attribute group errors before returning
this error. this error.
2.1.1.4.2 Ignore unknown attribute groups in the expected position Expires August 12, 1999
2.2.1.4.2 Ignore unknown attribute groups in the expected position
Future attribute groups may be added to the specification at the end of Future attribute groups may be added to the specification at the end of
requests just before the Document Content and at the end of response, requests just before the Document Content and at the end of response,
except for the Get-Jobs response, where it maybe there or before the except for the Get-Jobs response, where it maybe there or before the
first job attributes returned. If an IPP object receives an unknown first job attributes returned. If an IPP object receives an unknown
attribute group in these positions, it ignores the entire group, rather attribute group in these positions, it ignores the entire group, rather
than returning an error, since that group may be a new group in a later than returning an error, since that group may be a new group in a later
minor version of the protocol that can be ignored. (If the new minor version of the protocol that can be ignored. (If the new
attribute group cannot be ignored without confusing the client, the attribute group cannot be ignored without confusing the client, the
major version number would have been increased in the protocol document major version number would have been increased in the protocol document
skipping to change at page 9, line 5 skipping to change at page 12, line 28
position, the IPP object REJECTS the request and RETURNS the 'client- position, the IPP object REJECTS the request and RETURNS the 'client-
error-bad-request' status code. error-bad-request' status code.
Clients also ignore unknown attribute groups returned in a response. Clients also ignore unknown attribute groups returned in a response.
Note: By validating that requests are in the proper form, IPP objects Note: By validating that requests are in the proper form, IPP objects
force clients to use the proper form which, in turn, increases the force clients to use the proper form which, in turn, increases the
chances that customers will be able to use such clients from multiple chances that customers will be able to use such clients from multiple
vendors with IPP objects from other vendors. vendors with IPP objects from other vendors.
Expires May 16, 1999 2.2.1.4.3 Validate the presence of a single occurrence of required
2.1.1.4.3 Validate the presence of a single occurrence of required
Operation attributes Operation attributes
Client requests and IPP object responses contain Operation attributes Client requests and IPP object responses contain Operation attributes
that [IPP-MOD] Section 3 requires to be present. Attributes within a that [IPP-MOD] Section 3 requires to be present. Attributes within a
group may be in any order, except for the ordering of target, charset, group may be in any order, except for the ordering of target, charset,
and natural languages attributes. These attributes MUST be first, and and natural languages attributes. These attributes MUST be first, and
MUST be supplied in the following order: charset, natural language, and MUST be supplied in the following order: charset, natural language, and
then target. An IPP object verifies that the attributes that Section 4 then target. An IPP object verifies that the attributes that Section 4
requires to be supplied by the client have been supplied in the request requires to be supplied by the client have been supplied in the request
(attributes without an * in the following tables). An asterisk (*) (attributes without an * in the following tables). An asterisk (*)
indicates groups and Operation attributes that the client may omit in a indicates groups and Operation attributes that the client may omit in a
request or an IPP object may omit in a response. request or an IPP object may omit in a response.
If an IPP object receives a request with required attributes missing or If an IPP object receives a request with required attributes missing or
repeated from a group, the IPP object REJECTS the request and RETURNS repeated from a group or in the wrong position, the behavior of the IPP
the 'client-error-bad-request' status code. For example, it is an error object is IMPLEMENTATION DEPENDENT. Some of the possible
for the "attributes-charset" or "attributes-natural-language" attribute implementations are:
to be omitted in any operation request, or for an Operation attribute to
be supplied in a Job Template group or a Job Template attribute to be 1.REJECTS the request and RETURNS the 'client-error-bad-request'
supplied in an Operation Attribute group in a create request. It is status code
also an error to supply the "attributes-charset" attribute twice.
2.accepts the request and uses the first occurrence of the
attribute no matter where it is
3.accepts the request and uses the last occurrence of the
attribute no matter where it is
4.accept the request and assume some default value for the missing
attribute
Expires August 12, 1999
Therefore, client MUST send conforming requests, if they want to receive
the same behavior from all IPP object implementations. For example, it
is an error for the "attributes-charset" or "attributes-natural-
language" attribute to be omitted in any operation request, or for an
Operation attribute to be supplied in a Job Template group or a Job
Template attribute to be supplied in an Operation Attribute group in a
create request. It is also an error to supply the "attributes-charset"
attribute twice.
Since these kinds of attribute errors are most likely to be detected by Since these kinds of attribute errors are most likely to be detected by
a client developer rather than by a customer, the IPP object NEED NOT a client developer rather than by a customer, the IPP object NEED NOT
return an indication of which attribute was in error in either the return an indication of which attribute was in error in either the
Unsupported Attributes group or the Status Message. Also, the IPP Unsupported Attributes group or the Status Message. Also, the IPP
object NEED NOT find all attribute errors before returning this error. object NEED NOT find all attribute errors before returning this error.
The following tables list all the attributes for all the operations by The following tables list all the attributes for all the operations by
attribute group in each request and each response. The order of the attribute group in each request and each response. The order of the
groups is the order that the client supplies the groups as specified in groups is the order that the client supplies the groups as specified in
skipping to change at page 10, line 5 skipping to change at page 14, line 5
supply the attribute in a response. supply the attribute in a response.
Operation Requests Operation Requests
The tables below show the attributes in their proper attribute groups The tables below show the attributes in their proper attribute groups
for operation requests: for operation requests:
Note: All operation requests contain "version-number", "operation-id", Note: All operation requests contain "version-number", "operation-id",
and "request-id" parameters. and "request-id" parameters.
Expires May 16, 1999 Expires August 12, 1999
Expires May 16, 1999
Print-Job Request: Print-Job Request:
Group 1: Operation Attributes (R) Group 1: Operation Attributes (R)
attributes-charset (R) attributes-charset (R)
attributes-natural-language (R) attributes-natural-language (R)
printer-uri (R) printer-uri (R)
requesting-user-name (R*) requesting-user-name (R*)
job-name (R*) job-name (R*)
ipp-attribute-fidelity (R*) ipp-attribute-fidelity (R*)
document-name (R*) document-name (R*)
document-format (R*) document-format (R*)
skipping to change at page 12, line 5 skipping to change at page 15, line 5
requesting-user-name (R*) requesting-user-name (R*)
job-name (R*) job-name (R*)
ipp-attribute-fidelity (R*) ipp-attribute-fidelity (R*)
job-k-octets (O*) job-k-octets (O*)
job-impressions (O*) job-impressions (O*)
job-media-sheets (O*) job-media-sheets (O*)
Group 2: Job Template Attributes (R*) Group 2: Job Template Attributes (R*)
<Job Template attributes> (O*) (see <Job Template attributes> (O*) (see
(see [IPP-MOD] Section 4.2) (see [IPP-MOD] Section 4.2)
Expires May 16, 1999 Expires August 12, 1999
Print-URI Request: Print-URI Request:
Group 1: Operation Attributes (R) Group 1: Operation Attributes (R)
attributes-charset (R) attributes-charset (R)
attributes-natural-language (R) attributes-natural-language (R)
printer-uri (R) printer-uri (R)
document-uri (R) document-uri (R)
requesting-user-name (R*) requesting-user-name (R*)
job-name (R*) job-name (R*)
ipp-attribute-fidelity (R*) ipp-attribute-fidelity (R*)
skipping to change at page 13, line 5 skipping to change at page 16, line 5
document-natural-language (O*) document-natural-language (O*)
compression (O*) compression (O*)
Cancel-Job Request: Cancel-Job Request:
Group 1: Operation Attributes (R) Group 1: Operation Attributes (R)
attributes-charset (R) attributes-charset (R)
attributes-natural-language (R) attributes-natural-language (R)
(printer-uri & job-id) | job-uri (R) (printer-uri & job-id) | job-uri (R)
requesting-user-name (R*) requesting-user-name (R*)
Expires May 16, 1999 Expires August 12, 1999
message (O*) message (O*)
Get-Printer-Attributes Request: Get-Printer-Attributes Request:
Group 1: Operation Attributes (R) Group 1: Operation Attributes (R)
attributes-charset (R) attributes-charset (R)
attributes-natural-language (R) attributes-natural-language (R)
printer-uri (R) printer-uri (R)
requesting-user-name (R*) requesting-user-name (R*)
requested-attributes (R*) requested-attributes (R*)
document-format (R*) document-format (R*)
skipping to change at page 14, line 5 skipping to change at page 17, line 5
my-jobs (R*) my-jobs (R*)
Operation Responses Operation Responses
The tables below show the response attributes in their proper attribute The tables below show the response attributes in their proper attribute
groups for responses. groups for responses.
Note: All operation responses contain "version-number", "status-code", Note: All operation responses contain "version-number", "status-code",
and "request-id" parameters. and "request-id" parameters.
Expires May 16, 1999 Expires August 12, 1999
Print-Job Response: Print-Job Response:
Print-URI Response: Print-URI Response:
Create-Job Response: Create-Job Response:
Send-Document Response: Send-Document Response:
Send-URI Response: Send-URI Response:
Group 1: Operation Attributes (R) Group 1: Operation Attributes (R)
attributes-charset (R) attributes-charset (R)
attributes-natural-language (R) attributes-natural-language (R)
status-message (O*) status-message (O*)
Group 2: Unsupported Attributes (R*) (see Note 3) Group 2: Unsupported Attributes (R*) (see Note 3)
skipping to change at page 15, line 5 skipping to change at page 18, line 5
status-message (O*) status-message (O*)
Group 2: Unsupported Attributes (R*) (see Note 4) Group 2: Unsupported Attributes (R*) (see Note 4)
<unsupported attributes> (R*) <unsupported attributes> (R*)
Group 3: Printer Object Attributes(R*) (see Note 2) Group 3: Printer Object Attributes(R*) (see Note 2)
<requested attributes> (R*) <requested attributes> (R*)
Note 4 - the Unsupported Attributes Group is present only if the client Note 4 - the Unsupported Attributes Group is present only if the client
included some Operation attributes that the Printer doesn't support included some Operation attributes that the Printer doesn't support
whether a success or an error return. whether a success or an error return.
Expires May 16, 1999 Expires August 12, 1999
Get-Job-Attributes Response: Get-Job-Attributes Response:
Group 1: Operation Attributes (R) Group 1: Operation Attributes (R)
attributes-charset (R) attributes-charset (R)
attributes-natural-language (R) attributes-natural-language (R)
status-message (O*) status-message (O*)
Group 2: Unsupported Attributes (R*) (see Note 4) Group 2: Unsupported Attributes (R*) (see Note 4)
<unsupported attributes> (R*) <unsupported attributes> (R*)
Group 3: Job Object Attributes(R*) (see Note 2) Group 3: Job Object Attributes(R*) (see Note 2)
<requested attributes> (R*) <requested attributes> (R*)
skipping to change at page 15, line 30 skipping to change at page 18, line 30
status-message (O*) status-message (O*)
Group 2: Unsupported Attributes (R*) (see Note 4) Group 2: Unsupported Attributes (R*) (see Note 4)
<unsupported attributes> (R*) <unsupported attributes> (R*)
Group 3: Job Object Attributes(R*) (see Note 2, 5) Group 3: Job Object Attributes(R*) (see Note 2, 5)
<requested attributes> (R*) <requested attributes> (R*)
Note 5: for the Get-Jobs operation the response contains a separate Job Note 5: for the Get-Jobs operation the response contains a separate Job
Object Attributes group 3 to N containing requested-attributes for each Object Attributes group 3 to N containing requested-attributes for each
job object in the response. job object in the response.
2.1.1.5 Validate the values of the REQUIRED Operation attributes 2.2.1.5 Validate the values of the REQUIRED Operation attributes
An IPP object validates the values supplied by the client of the An IPP object validates the values supplied by the client of the
REQUIRED Operation attribute that the IPP object MUST support. The next REQUIRED Operation attribute that the IPP object MUST support. The next
section specifies the validation of the values of the OPTIONAL Operation section specifies the validation of the values of the OPTIONAL Operation
attributes that IPP objects MAY support. attributes that IPP objects MAY support.
The IPP object performs the following syntactic validation checks of The IPP object performs the following syntactic validation checks of
each Operation attribute value: each Operation attribute value:
a)that the length of each Operation attribute value is correct for a)that the length of each Operation attribute value is correct for
skipping to change at page 16, line 5 skipping to change at page 19, line 5
d)that multiple values are supplied by the client only for d)that multiple values are supplied by the client only for
operation attributes that are multi-valued, i.e., that are operation attributes that are multi-valued, i.e., that are
1setOf X according to [IPP-MOD] Section 3. 1setOf X according to [IPP-MOD] Section 3.
If any of these checks fail, the IPP object REJECTS the request and If any of these checks fail, the IPP object REJECTS the request and
RETURNS the 'client-error-bad-request' or the 'client-error-request- RETURNS the 'client-error-bad-request' or the 'client-error-request-
value-too-long' status code. Since such an error is most likely to be value-too-long' status code. Since such an error is most likely to be
an error detected by a client developer, rather than by an end-user, the an error detected by a client developer, rather than by an end-user, the
Expires May 16, 1999 Expires August 12, 1999
IPP object NEED NOT return an indication of which attribute had the IPP object NEED NOT return an indication of which attribute had the
error in either the Unsupported Attributes Group or the Status Message. error in either the Unsupported Attributes Group or the Status Message.
The description for each of these syntactic checks is explicitly The description for each of these syntactic checks is explicitly
expressed in the first IF statement in the following table. expressed in the first IF statement in the following table.
In addition, the IPP object checks each Operation attribute value In addition, the IPP object checks each Operation attribute value
against some Printer object attribute or some hard-coded value if there against some Printer object attribute or some hard-coded value if there
is no "xxx-supported" Printer object attribute defined. If its value is is no "xxx-supported" Printer object attribute defined. If its value is
not among those supported or is not in the range supported, then the IPP not among those supported or is not in the range supported, then the IPP
object REJECTS the request and RETURNS the error status code indicated object REJECTS the request and RETURNS the error status code indicated
in the table by the second IF statement. If the value of the Printer in the table by the second IF statement. If the value of the Printer
object's "xxx-supported" attribute is 'no-value' (because the system object's "xxx-supported" attribute is 'no-value' (because the system
administrator hasn't configured a value), the check always fails. administrator hasn't configured a value), the check always fails.
----------------------------------------------- -----------------------------------------------
attributes-charset (charset) attributes-charset (charset)
IF NOT any single non-empty 'charset' value less than or equal to 63 IF NOT a single non-empty 'charset' value, REJECT/RETURN 'client-
octets, REJECT/RETURN 'client-error-request-value-too-long'. error-request-bad-request'.
IF the value length is greater than 63 octets, REJECT/RETURN 'client-
error-request-value-too-long'.
IF NOT in the Printer object's "charset-supported" attribute, IF NOT in the Printer object's "charset-supported" attribute,
REJECT/RETURN "client-error-charset-not-supported". REJECT/RETURN "client-error-charset-not-supported".
attributes-natural-language(naturalLanguage) attributes-natural-language(naturalLanguage)
IF NOT any single non-empty 'naturalLanguage' value less than or IF NOT a single non-empty 'naturalLanguage' value, REJECT/RETURN
equal to 63 octets, REJECT/RETURN 'client-error-request-value-too- 'client-error-request-bad-request'.
long'. IF the value length is greater than 63 octets, REJECT/RETURN 'client-
error-request-value-too-long'.
ACCEPT the request even if not a member of the set in the Printer ACCEPT the request even if not a member of the set in the Printer
object's "generated-natural-language-supported" attribute. object's "generated-natural-language-supported" attribute. If the
supplied value is not a member of the Printer object's "generated-
natural-language-supported" attribute, use the Printer object's
"natural-language-configured" value.
requesting-user-name requesting-user-name
IF NOT any single 'name' value less than or equal to 255 octets, IF NOT a single 'name' value, REJECT/RETURN 'client-error-request-
REJECT/RETURN 'client-error-request-value-too-long'. bad-request'.
IF the value length is greater than 255 octets, REJECT/RETURN
'client-error-request-value-too-long'.
IF the IPP object can obtain a better authenticated name, use it IF the IPP object can obtain a better authenticated name, use it
instead. instead.
job-name(name) job-name(name)
IF NOT any single 'name' value less than or equal to 255 octets, IF NOT a single 'name' value, REJECT/RETURN 'client-error-request-
REJECT/RETURN 'client-error-request-value-too-long'. bad-request'.
IF the value length is greater than 255 octets, REJECT/RETURN
'client-error-request-value-too-long'.
IF NOT supplied by the client, the Printer object creates a name from IF NOT supplied by the client, the Printer object creates a name from
the document-name or document-uri. the document-name or document-uri.
Expires August 12, 1999
document-name (name) document-name (name)
IF NOT any single 'name' value less than or equal to 255 octets, IF NOT a single 'name' value, REJECT/RETURN 'client-error-request-
REJECT/RETURN 'client-error-request-value-too-long'. bad-request'.
IF the value length is greater than 255 octets, REJECT/RETURN
'client-error-request-value-too-long'.
ipp-attribute-fidelity (boolean) ipp-attribute-fidelity (boolean)
IF NOT either a single 'true' or 'false' 'boolean' value equal to 1 IF NEITHER a single 'true' NOR a single 'false' 'boolean' value,
octet, REJECT/RETURN 'client-error-bad-request'. REJECT/RETURN 'client-error-bad-request'.
IF the value length is NOT equal to 1 octet, REJECT/RETURN 'client-
Expires May 16, 1999 error-request-value-too-long'
IF NOT supplied by the client, the IPP object assumes the value IF NOT supplied by the client, the IPP object assumes the value
'false'. 'false'.
document-format (mimeMediaType) document-format (mimeMediaType)
IF NOT any single non-empty 'mimeMediaType' value less than or equal IF NOT a single non-empty 'mimeMediaType' value, REJECT/RETURN
to 255 octets, REJECT/RETURN 'client-error-request-value-too-long'. 'client-error-request-bad-request'.
IF the value length is greater than 255 octets, REJECT/RETURN
'client-error-request-value-too-long'.
IF NOT in the Printer object's "document-format-supported" attribute, IF NOT in the Printer object's "document-format-supported" attribute,
REJECT/RETURN 'client-error-document-format-not-supported' REJECT/RETURN 'client-error-document-format-not-supported'
IF NOT supplied by the client, the IPP object assumes the value of IF NOT supplied by the client, the IPP object assumes the value of
the Printer object's "document-format-default" attribute. the Printer object's "document-format-default" attribute.
document-uri (uri) document-uri (uri)
IF NOT any single non-empty 'uri' value less than or equal to 1023 IF NOT a single non-empty 'uri' value, REJECT/RETURN 'client-error-
octets, REJECT/RETURN 'client-error-request-value-too-long'. request-bad-request'.
IF the value length is greater than 1023 octets, REJECT/RETURN
'client-error-request-value-too-long'.
IF the URI syntax is not valid, REJECT/RETURN 'client-error-bad- IF the URI syntax is not valid, REJECT/RETURN 'client-error-bad-
request'. request'.
IF scheme is NOT in the Printer object's "reference-uri-schemes- IF scheme is NOT in the Printer object's "reference-uri-schemes-
supported" attribute, REJECT/RETURN 'client-error'-uri-scheme-not- supported" attribute, REJECT/RETURN 'client-error-uri-scheme-not-
supported'. supported'.
The Printer object MAY check to see if the document exists and is
accessible. If the document is not found or is not accessible,
REJECT/RETURN 'client-error-not found'.
last-document (boolean) last-document (boolean)
IF NOT either a single 'true' or 'false' 'boolean' value equal to 1 IF NEITHER a single 'true' NOR a single 'false' 'boolean' value,
octet, REJECT/RETURN 'client-error-bad-request'. REJECT/RETURN 'client-error-bad-request'.
IF the value length is NOT equal to 1 octet, REJECT/RETURN 'client-
error-request-value-too-long'
job-id (integer(1:MAX)) job-id (integer(1:MAX))
IF NOT any single 'integer' value equal to 4 octets AND in the range IF NOT an single 'integer' value equal to 4 octets AND in the range 1
1 to MAX, REJECT/RETURN 'client-error-bad-request'. to MAX, REJECT/RETURN 'client-error-bad-request'.
Expires August 12, 1999
IF NOT a job-id of an existing Job object, REJECT/RETURN 'client- IF NOT a job-id of an existing Job object, REJECT/RETURN 'client-
error-not-found' or 'client-error-gone' status code, if keep track error-not-found' or 'client-error-gone' status code, if keep track
of recently deleted jobs. of recently deleted jobs.
requested-attributes (1setOf keyword) requested-attributes (1setOf keyword)
IF NOT any number of 'keyword' values less than or equal to 255 IF NOT one or more 'keyword' values, REJECT/RETURN 'client-error-
octets, REJECT/RETURN 'client-error-request-value-too-long'. request-bad-request'.
IF the value length is greater than 255 octets, REJECT/RETURN
'client-error-request-value-too-long'.
Ignore unsupported values which are the keyword names of unsupported Ignore unsupported values which are the keyword names of unsupported
attributes. Don't bother to copy such requested (unsupported) attributes. Don't bother to copy such requested (unsupported)
attributes to the Unsupported Attribute response group since the attributes to the Unsupported Attribute response group since the
response will not return them. response will not return them.
which-jobs (type2 keyword) which-jobs (type2 keyword)
IF NOT a single 'keyword' value less than or equal to 255 octets, IF NOT a single 'keyword' value, REJECT/RETURN 'client-error-request-
REJECT/RETURN 'client-error-request-value-too-long'. bad-request'.
IF the value length is greater than 255 octets, REJECT/RETURN
'client-error-request-value-too-long'.
IF NEITHER 'completed' NOR 'not-completed', copy the attribute and IF NEITHER 'completed' NOR 'not-completed', copy the attribute and
the unsupported value to the Unsupported Attributes response group the unsupported value to the Unsupported Attributes response group
and REJECT/RETURN 'client-error-attributes-or-values-not- and REJECT/RETURN 'client-error-attributes-or-values-not-
supported'. supported'.
Expires May 16, 1999
Note: a Printer still supports the 'completed' value even if it keeps Note: a Printer still supports the 'completed' value even if it keeps
no completed/canceled/aborted jobs: by returning no jobs when so no completed/canceled/aborted jobs: by returning no jobs when so
queried. queried.
IF NOT supplied by the client, the IPP object assumes the 'not- IF NOT supplied by the client, the IPP object assumes the 'not-
completed' value. completed' value.
my-jobs (boolean) my-jobs (boolean)
IF NOT either a single 'true' or 'false' 'boolean' value equal to 1 IF NEITHER a single 'true' NOR a single 'false' 'boolean' value,
octet, REJECT/RETURN 'client-error-bad-request'. REJECT/RETURN 'client-error-bad-request'.
IF the value length is NOT equal to 1 octet, REJECT/RETURN 'client-
error-request-value-too-long'
IF NOT supplied by the client, the IPP object assumes the 'false' IF NOT supplied by the client, the IPP object assumes the 'false'
value. value.
limit (integer(1:MAX)) limit (integer(1:MAX))
IF NOT any single 'integer' value equal to 4 octets AND in the range IF NOT a single 'integer' value equal to 4 octets AND in the range 1
1 to MAX, REJECT/RETURN 'client-error-bad-request'. to MAX, REJECT/RETURN 'client-error-bad-request'.
IF NOT supplied by the client, the IPP object returns all jobs, no IF NOT supplied by the client, the IPP object returns all jobs, no
matter how many. matter how many.
----------------------------------------------- -----------------------------------------------
2.1.1.6 Validate the values of the OPTIONAL Operation attributes Expires August 12, 1999
2.2.1.6 Validate the values of the OPTIONAL Operation attributes
OPTIONAL Operation attributes are those that an IPP object MAY or MAY OPTIONAL Operation attributes are those that an IPP object MAY or MAY
NOT support. An IPP object validates the values of the OPTIONAL NOT support. An IPP object validates the values of the OPTIONAL
attributes supplied by the client. The IPP object performs the same attributes supplied by the client. The IPP object performs the same
syntactic validation checks for each OPTIONAL attribute value as in syntactic validation checks for each OPTIONAL attribute value as in
Section 2.1.1.5. As in Section 2.1.1.5, if any fail, the IPP object Section 2.2.1.5. As in Section 2.2.1.5, if any fail, the IPP object
REJECTS the request and RETURNS the 'client-error-bad-request' or the REJECTS the request and RETURNS the 'client-error-bad-request' or the
'client-error-request-value-too-long' status code. 'client-error-request-value-too-long' status code.
In addition, the IPP object checks each Operation attribute value In addition, the IPP object checks each Operation attribute value
against some Printer attribute or some hard-coded value if there is no against some Printer attribute or some hard-coded value if there is no
"xxx-supported" Printer attribute defined. If its value is not among "xxx-supported" Printer attribute defined. If its value is not among
those supported or is not in the range supported, then the IPP object those supported or is not in the range supported, then the IPP object
REJECTS the request and RETURNS the error status code indicated in the REJECTS the request and RETURNS the error status code indicated in the
table. If the value of the Printer object's "xxx-supported" attribute table. If the value of the Printer object's "xxx-supported" attribute
is 'no-value' (because the system administrator hasn't configured a is 'no-value' (because the system administrator hasn't configured a
value), the check always fails. value), the check always fails.
If the IPP object doesn't recognize/support an attribute, the IPP object If the IPP object doesn't recognize/support an attribute, the IPP object
treats the attribute as an unknown or unsupported attribute (see the treats the attribute as an unknown or unsupported attribute (see the
last row in the table below). last row in the table below).
----------------------------------------------- -----------------------------------------------
document-natural-language (naturalLanguage) document-natural-language (naturalLanguage)
IF NOT any single non-empty 'naturalLanguage' value less than or IF NOT a single non-empty 'naturalLanguage' value, REJECT/RETURN
equal to 63 octets, REJECT/RETURN 'client-error-request-value-too- 'client-error-request-bad-request'.
long'. IF the value length is greater than 63 octets, REJECT/RETURN 'client-
error-request-value-too-long'.
Expires May 16, 1999
IF NOT a value that the Printer object supports in document formats, IF NOT a value that the Printer object supports in document formats,
(no corresponding "xxx-supported" Printer attribute), REJECT/RETURN (no corresponding "xxx-supported" Printer attribute), REJECT/RETURN
'client-error-natural-language-not-supported'. 'client-error-natural-language-not-supported'.
compression (type3 keyword) compression (type3 keyword)
IF NOT any single 'keyword' values less than or equal to 255 octets, IF NOT a single 'keyword' value, REJECT/RETURN 'client-error-request-
REJECT/RETURN 'client-error-request-value-too-long'. bad-request'.
IF the value length is greater than 255 octets, REJECT/RETURN
'client-error-request-value-too-long'.
IF NOT in the Printer object's "compression-supported" attribute, IF NOT in the Printer object's "compression-supported" attribute,
copy the attribute and the unsupported value to the Unsupported copy the attribute and the unsupported value to the Unsupported
Attributes response group and REJECT/RETURN 'client-error- Attributes response group and REJECT/RETURN 'client-error-
attributes-or-values-not-supported'. attributes-or-values-not-supported'.
job-k-octets (integer(0:MAX)) job-k-octets (integer(0:MAX))
IF NOT any single 'integer' value equal to 4 octets, IF NOT a single 'integer' value equal to 4 octets,
REJECT/RETURN 'client-error-bad-request'. REJECT/RETURN 'client-error-bad-request'.
IF NOT in the range of the Printer object's "job-k-octets-supported" IF NOT in the range of the Printer object's "job-k-octets-supported"
attribute, copy the attribute and the unsupported value to the attribute, copy the attribute and the unsupported value to the
Unsupported Attributes response group and REJECT/RETURN 'client- Unsupported Attributes response group and REJECT/RETURN 'client-
error-attributes-or-values-not-supported'. error-attributes-or-values-not-supported'.
Expires August 12, 1999
job-impressions (integer(0:MAX)) job-impressions (integer(0:MAX))
IF NOT any single 'integer' value equal to 4 octets, IF NOT a single 'integer' value equal to 4 octets,
REJECT/RETURN 'client-error-bad-request'. REJECT/RETURN 'client-error-bad-request'.
IF NOT in the range of the Printer object's "job-impressions- IF NOT in the range of the Printer object's "job-impressions-
supported" attribute, copy the attribute and the unsupported value supported" attribute, copy the attribute and the unsupported value
to the Unsupported Attributes response group and REJECT/RETURN to the Unsupported Attributes response group and REJECT/RETURN
'client-error-attributes-or-values-not-supported'. 'client-error-attributes-or-values-not-supported'.
job-media-sheets (integer(0:MAX)) job-media-sheets (integer(0:MAX))
IF NOT any single 'integer' value equal to 4 octets, IF NOT a single 'integer' value equal to 4 octets,
REJECT/RETURN 'client-error-bad-request'. REJECT/RETURN 'client-error-bad-request'.
IF NOT in the range of the Printer object's "job-media-supported" IF NOT in the range of the Printer object's "job-media-sheets-
attribute, copy the attribute and the unsupported value to the supported" attribute, copy the attribute and the unsupported value
Unsupported Attributes response group and REJECT/RETURN 'client- to the Unsupported Attributes response group and REJECT/RETURN
error-attributes-or-values-not-supported'. 'client-error-attributes-or-values-not-supported'.
message (text(127)) message (text(127))
IF NOT any single 'text' value less than or equal to 127 octets, IF NOT a single 'text' value, REJECT/RETURN 'client-error-request-
bad-request'.
IF the value length is greater than 127 octets,
REJECT/RETURN 'client-error-request-value-too-long'. REJECT/RETURN 'client-error-request-value-too-long'.
unknown or unsupported attribute unknown or unsupported attribute
IF the attribute syntax supplied by the client is supported but the IF the attribute syntax supplied by the client is supported but the
length is not legal for that attribute syntax, REJECT/RETURN length is not legal for that attribute syntax, REJECT/RETURN
'client-error-request-value-too-long'. 'client-error-request-value-too-long'.
ELSE copy the attribute and value to the Unsupported Attributes ELSE copy the attribute and value to the Unsupported Attributes
response group and change the attribute value to the "out-of-band" response group and change the attribute value to the "out-of-band"
'unsupported' value, but otherwise ignore the attribute. 'unsupported' value, but otherwise ignore the attribute.
Expires May 16, 1999
Note: Future Operation attributes may be added to the protocol Note: Future Operation attributes may be added to the protocol
specification that may occur anywhere in the specified group. When specification that may occur anywhere in the specified group. When
the operation is otherwise successful, the IPP object returns the the operation is otherwise successful, the IPP object returns the
'successful-ok-ignored-or-substituted-attributes' status code. 'successful-ok-ignored-or-substituted-attributes' status code.
Ignoring unsupported Operation attributes in all operations is Ignoring unsupported Operation attributes in all operations is
analogous to the handling of unsupported Job Template attributes in analogous to the handling of unsupported Job Template attributes in
the create and Validate-Job operations when the client supplies the the create and Validate-Job operations when the client supplies the
"ipp-attribute-fidelity" Operation attribute with the 'false' value. "ipp-attribute-fidelity" Operation attribute with the 'false' value.
This last rule is so that we can add OPTIONAL Operation attributes to This last rule is so that we can add OPTIONAL Operation attributes to
future versions of IPP so that older clients can inter-work with new future versions of IPP so that older clients can inter-work with new
IPP objects and newer clients can inter-work with older IPP objects. IPP objects and newer clients can inter-work with older IPP objects.
(If the new attribute cannot be ignored without performing (If the new attribute cannot be ignored without performing
unexpectedly, the major version number would have been increased in unexpectedly, the major version number would have been increased in
the protocol document and in the request). This rule for Operation the protocol document and in the request). This rule for Operation
attributes is independent of the value of the "ipp-attribute- attributes is independent of the value of the "ipp-attribute-
fidelity" attribute. For example, if an IPP object doesn't support fidelity" attribute. For example, if an IPP object doesn't support
the OPTIONAL "job-k-octets" attribute', the IPP object treats "job-k- the OPTIONAL "job-k-octets" attribute', the IPP object treats "job-k-
octets" as an unknown attribute and only checks the length for the octets" as an unknown attribute and only checks the length for the
'integer' attribute syntax supplied by the client. If it is not four 'integer' attribute syntax supplied by the client. If it is not four
Expires August 12, 1999
octets, the IPP object REJECTS the request and RETURNS the 'client- octets, the IPP object REJECTS the request and RETURNS the 'client-
error-bad-request' status code, else the IPP object copies the error-bad-request' status code, else the IPP object copies the
attribute to the Unsupported Attribute response group, setting the attribute to the Unsupported Attribute response group, setting the
value to the "out-of-band" 'unsupported' value, but otherwise ignores value to the "out-of-band" 'unsupported' value, but otherwise ignores
the attribute. the attribute.
2.1.2Suggested Additional Processing Steps for Operations that 2.2.2Suggested Additional Processing Steps for Operations that
Create/Validate Jobs and Add Documents Create/Validate Jobs and Add Documents
This section in combination with the previous section recommends the This section in combination with the previous section recommends the
processing steps for the Print-Job, Validate-Job, Print-URI, Create-Job, processing steps for the Print-Job, Validate-Job, Print-URI, Create-Job,
Send-Document, and Send-URI operations that IPP objects SHOULD use. Send-Document, and Send-URI operations that IPP objects SHOULD use.
These are the operations that create jobs, validate a Print-Job request, These are the operations that create jobs, validate a Print-Job request,
and add documents to a job. and add documents to a job.
2.1.2.1 Default "ipp-attribute-fidelity" if not supplied 2.2.2.1 Default "ipp-attribute-fidelity" if not supplied
The Printer object checks to see if the client supplied an "ipp- The Printer object checks to see if the client supplied an "ipp-
attribute-fidelity" Operation attribute. If the attribute is not attribute-fidelity" Operation attribute. If the attribute is not
supplied by the client, the IPP object assumes that the value is supplied by the client, the IPP object assumes that the value is
'false'. 'false'.
2.1.2.2 Check that the Printer object is accepting jobs 2.2.2.2 Check that the Printer object is accepting jobs
If the value of the Printer object's "printer-is-accepting-jobs" is If the value of the Printer object's "printer-is-accepting-jobs" is
'false', the Printer object REJECTS the request and RETURNS the 'server- 'false', the Printer object REJECTS the request and RETURNS the 'server-
error-not-accepting-jobs' status code. error-not-accepting-jobs' status code.
2.1.2.3 Validate the values of the Job Template attributes 2.2.2.3 Validate the values of the Job Template attributes
An IPP object validates the values of all Job Template attribute An IPP object validates the values of all Job Template attribute
supplied by the client. The IPP object performs the analogous syntactic supplied by the client. The IPP object performs the analogous syntactic
Expires May 16, 1999
validation checks of each Job Template attribute value that it performs validation checks of each Job Template attribute value that it performs
for Operation attributes (see Section 2.1.1.5.): for Operation attributes (see Section 2.2.1.5.):
a)that the length of each value is correct for the attribute a)that the length of each value is correct for the attribute
syntax tag supplied by the client according to [IPP-MOD] Section syntax tag supplied by the client according to [IPP-MOD] Section
4.1. 4.1.
b)that the attribute syntax tag is correct for that attribute b)that the attribute syntax tag is correct for that attribute
according to [IPP-MOD] Sections 4.2 to 4.4. according to [IPP-MOD] Sections 4.2 to 4.4.
c)that multiple values are supplied only for multi-valued c)that multiple values are supplied only for multi-valued
attributes, i.e., that are 1setOf X according to [IPP-MOD] attributes, i.e., that are 1setOf X according to [IPP-MOD]
Sections 4.2 to 4.4. Sections 4.2 to 4.4.
As in Section 2.1.1.5, if any of these syntactic checks fail, the IPP As in Section 2.2.1.5, if any of these syntactic checks fail, the IPP
object REJECTS the request and RETURNS the 'client-error-bad-request' or object REJECTS the request and RETURNS the 'client-error-bad-request' or
'client-error-request-value-too-long' status code as appropriate, 'client-error-request-value-too-long' status code as appropriate,
independent of the value of the "ipp-attribute-fidelity". Since such an independent of the value of the "ipp-attribute-fidelity". Since such an
error is most likely to be an error detected by a client developer, error is most likely to be an error detected by a client developer,
rather than by an end-user, the IPP object NEED NOT return an indication rather than by an end-user, the IPP object NEED NOT return an indication
Expires August 12, 1999
of which attribute had the error in either the Unsupported Attributes of which attribute had the error in either the Unsupported Attributes
Group or the Status Message. The description for each of these Group or the Status Message. The description for each of these
syntactic checks is explicitly expressed in the first IF statement in syntactic checks is explicitly expressed in the first IF statement in
the following table. the following table.
In addition, the IPP object loops through all the client-supplied Job Each Job Template attribute MUST occur no more than once. If an IPP
Template attributes, checking to see if the supplied attribute value(s) Printer receives a create request with multiple occurrences of a Job
are supported or in the range supported, i.e., the value of the "xxx" Template attribute, it MAY:
attribute in the request is (1) a member of the set of values or is in
the range of values of the Printer' objects "xxx-supported" attribute. 1.reject the operation and return the 'client-error-bad syntax'
error status code
2.accept the operation and use the first occurrence of the
attribute
3.accept the operation and use the last occurrence of the
attribute
depending on implementation. Therefore, clients MUST NOT supply
multiple occurrences of the same Job Template attribute in the Job
Attributes group in the request.
2.2.3Algorithm for job validation
The process of validating a Job-Template attribute "xxx" against a
Printer attribute "xxx-supported" can use the following validation
algorithm (see section 3.2.1.2 in [ipp-mod]).
To validate the value U of Job-Template attribute "xxx" against the
value V of Printer "xxx-supported", perform the following algorithm:
1.If U is multi-valued, validate each value X of U by performing
the algorithm in Table 3 with each value X. Each validation is
separate from the standpoint of returning unsupported values.
Example: If U is "finishings" that the client supplies with
'staple', 'bind' values, then X takes on the successive values:
'staple', then 'bind'
2.If V is multi-valued, validate X against each Z of V by
performing the algorithm in Table 3 with each value Z. If a
value Z validates, the validation for the attribute value X
succeeds. If it fails, the algorithm is applied to the next
value Z of V. If there are no more values Z of V, validation
fails.
Example" If V is "sides-supported" with values: 'one-sided',
'two-sided-long', and 'two-sided-short', then Z takes on the
successive values: 'one-sided', 'two-sided-long', and 'two-
sided-short'. If the client supplies "sides" with 'two-sided-
long', the first comparison fails ('one-sided' is not equal to
'two-sided-long'), the second comparison succeeds ('two-sided-
Expires August 12, 1999
long' is equal to 'two-sided-long"), and the third comparison
('two-sided-short' with 'two-sided-long') is not even performed.
3.If both U and V are single-valued, let X be U and Z be V and use
the validation rules in Table 3.
Table 3 - Rules for validating single values X against Z
attribute attribute validated if:
syntax of X syntax of Z
integer rangeOfInteger X is within the range of
Z
uri uriScheme the uri scheme in X is
equal to Z
any boolean the value of Z is TRUE
any any X and Z are of the same
type and are equal.
If the value of the Printer object's "xxx-supported" attribute is 'no- If the value of the Printer object's "xxx-supported" attribute is 'no-
value' (because the system administrator hasn't configured a value), the value' (because the system administrator hasn't configured a value), the
check always fails. If the check fails, the IPP object copies the check always fails. If the check fails, the IPP object copies the
attribute to the Unsupported Attributes response group with its attribute to the Unsupported Attributes response group with its
unsupported value. If the attribute contains more than one value, each unsupported value. If the attribute contains more than one value, each
value is checked and each unsupported value is separately copied, while value is checked and each unsupported value is separately copied, while
supported values are not copied. If an IPP object doesn't supported values are not copied. If an IPP object doesn't
recognize/support a Job Template attribute, i.e., there is no recognize/support a Job Template attribute, i.e., there is no
corresponding Printer object "xxx-supported" attribute, the IPP object corresponding Printer object "xxx-supported" attribute, the IPP object
treats the attribute as an unknown or unsupported attribute (see the treats the attribute as an unknown or unsupported attribute (see the
skipping to change at page 22, line 5 skipping to change at page 26, line 52
formats, the IPP object SHOULD take that into account in this validation formats, the IPP object SHOULD take that into account in this validation
using the value of the "document-format" supplied by the client (or using the value of the "document-format" supplied by the client (or
defaulted to the value of the Printer's "document-format-default" defaulted to the value of the Printer's "document-format-default"
attribute, if not supplied by the client). For example, if "number-up" attribute, if not supplied by the client). For example, if "number-up"
is supported for the 'text/plain' document format, but not for the is supported for the 'text/plain' document format, but not for the
'application/postscript' document format, the check SHOULD (though it 'application/postscript' document format, the check SHOULD (though it
NEED NOT) depend on the value of the "document-format" operation NEED NOT) depend on the value of the "document-format" operation
attribute. See "document-format" in [IPP-MOD] section 3.2.1.1 and attribute. See "document-format" in [IPP-MOD] section 3.2.1.1 and
3.2.5.1. 3.2.5.1.
Expires May 16, 1999
Note: whether the request is accepted or rejected is determined by the Note: whether the request is accepted or rejected is determined by the
value of the "ipp-attribute-fidelity" attribute in a subsequent step, so value of the "ipp-attribute-fidelity" attribute in a subsequent step, so
that all Job Template attribute supplied are examined and all that all Job Template attribute supplied are examined and all
unsupported attributes and/or values are copied to the Unsupported unsupported attributes and/or values are copied to the Unsupported
Attributes response group. Attributes response group.
----------------------------------------------- -----------------------------------------------
job-priority (integer(1:100)) job-priority (integer(1:100))
Expires August 12, 1999
IF NOT a single 'integer' value with a length equal to 4 octets, IF NOT a single 'integer' value with a length equal to 4 octets,
REJECT/RETURN 'client-error-bad-request'. REJECT/RETURN 'client-error-bad-request'.
IF NOT supplied by the client, use the value of the Printer object's IF NOT supplied by the client, use the value of the Printer object's
"job-priority-default" attribute at job submission time. "job-priority-default" attribute at job submission time.
IF NOT in the range 1 to 100, inclusive, copy the attribute and the IF NOT in the range 1 to 100, inclusive, copy the attribute and the
unsupported value to the Unsupported Attributes response group. unsupported value to the Unsupported Attributes response group.
Map the value to the nearest supported value in the range 1:100 as Map the value to the nearest supported value in the range 1:100 as
specified by the number of discrete values indicated by the value specified by the number of discrete values indicated by the value
of the Printer's "job-priority-supported" attribute. See the of the Printer's "job-priority-supported" attribute. See the
formula in [IPP-MOD] Section 4.2.1. formula in [IPP-MOD] Section 4.2.1.
job-hold-until (type3 keyword | name) job-hold-until (type3 keyword | name)
IF NOT a single 'keyword' or 'name' value with a length less than or IF NOT a single 'keyword' or 'name' value, REJECT/RETURN 'client-
equal to 255 octets, REJECT/RETURN 'client-error-request-value-too- error-request-bad-request'.
long'. IF the value length is greater than 255 octets, REJECT/RETURN
'client-error-request-value-too-long'.
IF NOT supplied by the client, use the value of the Printer object's IF NOT supplied by the client, use the value of the Printer object's
"job-hold-until" attribute at job submission time. "job-hold-until" attribute at job submission time.
IF NOT in the Printer object's "job-hold-until-supported" attribute, IF NOT in the Printer object's "job-hold-until-supported" attribute,
copy the attribute and the unsupported value to the Unsupported copy the attribute and the unsupported value to the Unsupported
Attributes response group. Attributes response group.
job-sheets (type3 keyword | name) job-sheets (type3 keyword | name)
IF NOT a single 'keyword' or 'name' value with a length less than or IF NOT a single 'keyword' or 'name' value, REJECT/RETURN 'client-
equal to 255 octets, REJECT/RETURN 'client-error-request-value-too- error-request-bad-request'.
long'. IF the value length is greater than 255 octets, REJECT/RETURN
'client-error-request-value-too-long'.
IF NOT in the Printer object's "job-sheets-supported" attribute, copy IF NOT in the Printer object's "job-sheets-supported" attribute, copy
the attribute and the unsupported value to the Unsupported the attribute and the unsupported value to the Unsupported
Attributes response group. Attributes response group.
multiple-document-handling (type2 keyword) multiple-document-handling (type2 keyword)
IF NOT a single 'keyword' value with a length less than or equal to IF NOT a single 'keyword' value, REJECT/RETURN 'client-error-request-
255 octets, REJECT/RETURN 'client-error-request-value-too-long'. bad-request'.
IF the value length is greater than 255 octets, REJECT/RETURN
'client-error-request-value-too-long'.
IF NOT in the Printer object's "multiple-document-handling-supported" IF NOT in the Printer object's "multiple-document-handling-supported"
attribute, copy the attribute and the unsupported value to the attribute, copy the attribute and the unsupported value to the
Unsupported Attributes response group. Unsupported Attributes response group.
copies (integer(1:MAX)) copies (integer(1:MAX))
IF NOT a single 'integer' value with a length equal to 4 octets, IF NOT a single 'integer' value with a length equal to 4 octets,
REJECT/RETURN 'client-error-bad-request'. REJECT/RETURN 'client-error-bad-request'.
IF NOT in range of the Printer object's "copies-supported" attribute IF NOT in range of the Printer object's "copies-supported" attribute
Expires May 16, 1999
copy the attribute and the unsupported value to the Unsupported copy the attribute and the unsupported value to the Unsupported
Attributes response group. Attributes response group.
finishings (1setOf type2 enum) finishings (1setOf type2 enum)
Expires August 12, 1999
IF NOT an 'enum' value(s) each with a length equal to 4 octets, IF NOT an 'enum' value(s) each with a length equal to 4 octets,
REJECT/RETURN 'client-error-bad-request'. REJECT/RETURN 'client-error-bad-request'.
IF NOT in the Printer object's "finishings-supported" attribute, copy IF NOT in the Printer object's "finishings-supported" attribute, copy
the attribute and the unsupported value(s), but not any supported the attribute and the unsupported value(s), but not any supported
values, to the Unsupported Attributes response group. values, to the Unsupported Attributes response group.
page-ranges (1setOf rangeOfInteger(1:MAX)) page-ranges (1setOf rangeOfInteger(1:MAX))
IF NOT a 'rangeOfInteger' value(s) each with a length equal to 8 IF NOT a 'rangeOfInteger' value(s) each with a length equal to 8
octets, REJECT/RETURN 'client-error-bad-request'. octets, REJECT/RETURN 'client-error-bad-request'.
IF first value is greater than second value in any range, the ranges IF first value is greater than second value in any range, the ranges
are not in ascending order, or ranges overlap, REJECT/RETURN are not in ascending order, or ranges overlap, REJECT/RETURN
'client-error-bad-request'. 'client-error-bad-request'.
IF the value of the Printer object's "page-ranges-supported" IF the value of the Printer object's "page-ranges-supported"
attribute is 'false', copy the attribute to the Unsupported attribute is 'false', copy the attribute to the Unsupported
Attributes response group and set the value to the "out-of-band" Attributes response group and set the value to the "out-of-band"
'unsupported' value. 'unsupported' value.
sides (type2 keyword) sides (type2 keyword)
IF NOT a single 'keyword' value with a length less than or equal to IF NOT a single 'keyword' value, REJECT/RETURN 'client-error-request-
255 octets, REJECT/RETURN 'client-error-request-value-too-long'. bad-request'.
IF the value length is greater than 255 octets, REJECT/RETURN
'client-error-request-value-too-long'.
IF NOT in the Printer object's "sides-supported" attribute, copy the IF NOT in the Printer object's "sides-supported" attribute, copy the
attribute and the unsupported value to the Unsupported Attributes attribute and the unsupported value to the Unsupported Attributes
response group. response group.
number-up (integer(1:MAX)) number-up (integer(1:MAX))
IF NOT a single 'integer' value with a length equal to 4 octets, IF NOT a single 'integer' value with a length equal to 4 octets,
REJECT/RETURN 'client-error-bad-request'. REJECT/RETURN 'client-error-bad-request'.
IF NOT a value or in the range of one of the values of the Printer IF NOT a value or in the range of one of the values of the Printer
object's "number-up-supported" attribute, copy the attribute and object's "number-up-supported" attribute, copy the attribute and
skipping to change at page 23, line 55 skipping to change at page 28, line 52
orientation-requested (type2 enum) orientation-requested (type2 enum)
IF NOT a single 'enum' value with a length equal to 4 octets, IF NOT a single 'enum' value with a length equal to 4 octets,
REJECT/RETURN 'client-error-bad-request'. REJECT/RETURN 'client-error-bad-request'.
IF NOT in the Printer object's "orientation-requested-supported" IF NOT in the Printer object's "orientation-requested-supported"
attribute, copy the attribute and the unsupported value to the attribute, copy the attribute and the unsupported value to the
Unsupported Attributes response group. Unsupported Attributes response group.
media (type3 keyword | name) media (type3 keyword | name)
IF NOT a single 'keyword' or 'name' value with a length less than or IF NOT a single 'keyword' or 'name' value, REJECT/RETURN 'client-
equal to 255 octets, REJECT/RETURN 'client-error-request-value-too- error-request-bad-request'.
long'. IF the value length is greater than 255 octets, REJECT/RETURN
'client-error-request-value-too-long'.
Expires May 16, 1999
IF NOT in the Printer object's "media-supported" attribute, copy the IF NOT in the Printer object's "media-supported" attribute, copy the
attribute and the unsupported value to the Unsupported Attributes attribute and the unsupported value to the Unsupported Attributes
response group. response group.
Expires August 12, 1999
printer-resolution (resolution) printer-resolution (resolution)
IF NOT a single 'resolution' value with a length equal to 9 octets, IF NOT a single 'resolution' value with a length equal to 9 octets,
REJECT/RETURN 'client-error-bad-request'. REJECT/RETURN 'client-error-bad-request'.
IF NOT in the Printer object's "multiple-document-handling-supported" IF NOT in the Printer object's "printer-resolution-supported"
attribute, copy the attribute and the unsupported value to the attribute, copy the attribute and the unsupported value to the
Unsupported Attributes response group. Unsupported Attributes response group.
print-quality (type2 enum) print-quality (type2 enum)
IF NOT a single 'enum' value with a length equal to 4 octets, IF NOT a single 'enum' value with a length equal to 4 octets,
REJECT/RETURN 'client-error-bad-request'. REJECT/RETURN 'client-error-bad-request'.
IF NOT in the Printer object's "print-quality-supported" attribute, IF NOT in the Printer object's "print-quality-supported" attribute,
copy the attribute and the unsupported value to the Unsupported copy the attribute and the unsupported value to the Unsupported
Attributes response group. Attributes response group.
skipping to change at page 25, line 5 skipping to change at page 30, line 5
object REJECTS the request and RETURNS the 'client-error-bad-request' if object REJECTS the request and RETURNS the 'client-error-bad-request' if
the length of the attribute syntax is fixed or the 'client-error- the length of the attribute syntax is fixed or the 'client-error-
request-value-too-long' status code if the length of the attribute request-value-too-long' status code if the length of the attribute
syntax is variable. Otherwise, the IPP object copies the unsupported Job syntax is variable. Otherwise, the IPP object copies the unsupported Job
Template attribute to the Unsupported Attributes response group and Template attribute to the Unsupported Attributes response group and
changes the attribute value to the "out-of-band" 'unsupported' value. changes the attribute value to the "out-of-band" 'unsupported' value.
The following table shows the length checks for all attribute syntaxes. The following table shows the length checks for all attribute syntaxes.
In the following table: "<=" means less than or equal, "=" means equal In the following table: "<=" means less than or equal, "=" means equal
to: to:
Expires May 16, 1999 Expires August 12, 1999
Name Octet length check for read-write attributes Name Octet length check for read-write attributes
----------- -------------------------------------------- ----------- --------------------------------------------
'textWithLanguage <= 1023 AND 'naturalLanguage' <= 63 'textWithLanguage <= 1023 AND 'naturalLanguage' <= 63
'textWithoutLanguage' <= 1023 'textWithoutLanguage' <= 1023
'nameWithLanguage' <= 255 AND 'naturalLanguage' <= 63 'nameWithLanguage' <= 255 AND 'naturalLanguage' <= 63
'nameWithoutLanguage' <= 255 'nameWithoutLanguage' <= 255
'keyword' <= 255 'keyword' <= 255
'enum' = 4 'enum' = 4
'uri' <= 1023 'uri' <= 1023
'uriScheme' <= 63 'uriScheme' <= 63
skipping to change at page 25, line 27 skipping to change at page 30, line 27
'naturalLanguage' <= 63 'naturalLanguage' <= 63
'mimeMediaType' <= 255 'mimeMediaType' <= 255
'octetString' <= 1023 'octetString' <= 1023
'boolean' = 1 'boolean' = 1
'integer' = 4 'integer' = 4
'rangeOfInteger' = 8 'rangeOfInteger' = 8
'dateTime' = 11 'dateTime' = 11
'resolution' = 9 'resolution' = 9
'1setOf X' '1setOf X'
2.1.2.4 Check for conflicting Job Template attributes values 2.2.3.1 Check for conflicting Job Template attributes values
Once all the Operation and Job Template attributes have been checked Once all the Operation and Job Template attributes have been checked
individually, the Printer object SHOULD check for any conflicting values individually, the Printer object SHOULD check for any conflicting values
among all the supported values supplied by the client. For example, a among all the supported values supplied by the client. For example, a
Printer object might be able to staple and to print on transparencies, Printer object might be able to staple and to print on transparencies,
however due to physical stapling constraints, the Printer object might however due to physical stapling constraints, the Printer object might
not be able to staple transparencies. The IPP object copies the not be able to staple transparencies. The IPP object copies the
supported attributes and their conflicting attribute values to the supported attributes and their conflicting attribute values to the
Unsupported Attributes response group. The Printer object only copies Unsupported Attributes response group. The Printer object only copies
over those attributes that the Printer object either ignores or over those attributes that the Printer object either ignores or
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'transparency', but the Printer object does not support stapling 'transparency', but the Printer object does not support stapling
transparencies. If the Printer chooses to ignore the stapling request transparencies. If the Printer chooses to ignore the stapling request
in order to resolve the conflict, the Printer objects returns in order to resolve the conflict, the Printer objects returns
"finishings" equal to 'staple' in the Unsupported Attributes response "finishings" equal to 'staple' in the Unsupported Attributes response
group. If any attributes are multi-valued, only the conflicting values group. If any attributes are multi-valued, only the conflicting values
of the attributes are copied. of the attributes are copied.
Note: The decisions made to resolve the conflict (if there is a choice) Note: The decisions made to resolve the conflict (if there is a choice)
is implementation dependent. is implementation dependent.
2.1.2.5 Decide whether to REJECT the request 2.2.3.2 Decide whether to REJECT the request
If there were any unsupported Job Template attributes or If there were any unsupported Job Template attributes or
unsupported/conflicting Job Template attribute values and the client unsupported/conflicting Job Template attribute values and the client
supplied the "ipp-attribute-fidelity" attribute with the 'true' value, supplied the "ipp-attribute-fidelity" attribute with the 'true' value,
the Printer object REJECTS the request and return the status code: the Printer object REJECTS the request and return the status code:
Expires May 16, 1999 Expires August 12, 1999
(1) 'client-error-conflicting-attributes' status code, if there were (1) 'client-error-conflicting-attributes' status code, if there were
any conflicts between attributes supplied by the client. any conflicts between attributes supplied by the client.
(2) 'client-error-attributes-or-values-not-supported' status code, (2) 'client-error-attributes-or-values-not-supported' status code,
otherwise. otherwise.
Note: Unsupported Operation attributes or values that are returned do Note: Unsupported Operation attributes or values that are returned do
not affect the status returned in this step. If the unsupported not affect the status returned in this step. If the unsupported
Operation attribute was a serious error, the above already rejected the Operation attribute was a serious error, the above already rejected the
request in a previous step. If control gets to this step with request in a previous step. If control gets to this step with
unsupported Operation attributes being returned, they are not serious unsupported Operation attributes being returned, they are not serious
errors. errors.
2.1.2.6 For the Validate-Job operation, RETURN one of the success 2.2.3.3 For the Validate-Job operation, RETURN one of the success
status codes status codes
If the requested operation is the Validate-Job operation, the Printer If the requested operation is the Validate-Job operation, the Printer
object returns: object returns:
(1) the "successful-ok" status code, if there are no unsupported or (1) the "successful-ok" status code, if there are no unsupported or
conflicting Job Template attributes or values. conflicting Job Template attributes or values.
(2) the "successful-ok-conflicting-attributes, if there are any (2) the "successful-ok-conflicting-attributes, if there are any
conflicting Job Template attribute or values. conflicting Job Template attribute or values.
(3) the "successful-ok-ignored-or-substituted-attributes, if there (3) the "successful-ok-ignored-or-substituted-attributes, if there
are only unsupported Job Template attributes or values. are only unsupported Job Template attributes or values.
Note: Unsupported Operation attributes or values that are returned do Note: Unsupported Operation attributes or values that are returned do
not affect the status returned in this step. If the unsupported not affect the status returned in this step. If the unsupported
Operation attribute was a serious error, the above already rejected the Operation attribute was a serious error, the above already rejected the
request in a previous step. If control gets to this step with request in a previous step. If control gets to this step with
unsupported Operation attributes being returned, they are not serious unsupported Operation attributes being returned, they are not serious
errors. errors.
2.1.2.7 Create the Job object with attributes to support 2.2.3.4 Create the Job object with attributes to support
If "ipp-attribute-fidelity" is set to 'false' (or it was not supplied by If "ipp-attribute-fidelity" is set to 'false' (or it was not supplied by
the client), the Printer object: the client), the Printer object:
(1) creates a Job object, assigns a unique value to the job's "job- (1) creates a Job object, assigns a unique value to the job's "job-
uri" and "job-id" attributes, and initializes all of the job's uri" and "job-id" attributes, and initializes all of the job's
other supported Job Description attributes. other supported Job Description attributes.
(2) removes all unsupported attributes from the Job object. (2) removes all unsupported attributes from the Job object.
(3) for each unsupported value, removes either the unsupported value (3) for each unsupported value, removes either the unsupported value
or substitutes the unsupported attribute value with some supported or substitutes the unsupported attribute value with some supported
value. If an attribute has no values after removing unsupported value. If an attribute has no values after removing unsupported
values from it, the attribute is removed from the Job object (so values from it, the attribute is removed from the Job object (so
that the normal default behavior at job processing time will take that the normal default behavior at job processing time will take
place for that attribute). place for that attribute).
(4) for each conflicting value, removes either the conflicting value (4) for each conflicting value, removes either the conflicting value
or substitutes the conflicting attribute value with some other or substitutes the conflicting attribute value with some other
supported value. If an attribute has no values after removing supported value. If an attribute has no values after removing
conflicting values from it, the attribute is removed from the Job conflicting values from it, the attribute is removed from the Job
Expires May 16, 1999 Expires August 12, 1999
object (so that the normal default behavior at job processing time object (so that the normal default behavior at job processing time
will take place for that attribute). will take place for that attribute).
If there were no attributes or values flagged as unsupported, or the If there were no attributes or values flagged as unsupported, or the
value of 'ipp-attribute-fidelity" was 'false', the Printer object is value of 'ipp-attribute-fidelity" was 'false', the Printer object is
able to accept the create request and create a new Job object. If the able to accept the create request and create a new Job object. If the
"ipp-attribute-fidelity" attribute is set to 'true', the Job Template "ipp-attribute-fidelity" attribute is set to 'true', the Job Template
attributes that populate the new Job object are necessarily all the Job attributes that populate the new Job object are necessarily all the Job
Template attributes supplied in the create request. If the "ipp- Template attributes supplied in the create request. If the "ipp-
attribute-fidelity" attribute is set to 'false', the Job Template attribute-fidelity" attribute is set to 'false', the Job Template
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default value mechanism. A default value for an attribute is used only default value mechanism. A default value for an attribute is used only
if the create request did not specify that attribute (or it was ignored if the create request did not specify that attribute (or it was ignored
when allowed by "ipp-attribute-fidelity" being 'false') and no value was when allowed by "ipp-attribute-fidelity" being 'false') and no value was
provided within the content of the document data. provided within the content of the document data.
If the client does not supply a value for some Job Template attribute, If the client does not supply a value for some Job Template attribute,
and the Printer does not support that attribute, as far as IPP is and the Printer does not support that attribute, as far as IPP is
concerned, the result of processing that Job (with respect to the concerned, the result of processing that Job (with respect to the
missing attribute) is undefined. missing attribute) is undefined.
Expires May 16, 1999 Expires August 12, 1999
2.1.2.8 Return one of the success status codes 2.2.3.5 Return one of the success status codes
Once the Job object has been created, the Printer object accepts the Once the Job object has been created, the Printer object accepts the
request and returns to the client: request and returns to the client:
(1) the 'successful-ok' status code, if there are no unsupported or (1) the 'successful-ok' status code, if there are no unsupported or
conflicting Job Template attributes or values. conflicting Job Template attributes or values.
(2) the 'successful-ok-conflicting-attributes' status code, if there (2) the 'successful-ok-conflicting-attributes' status code, if there
are any conflicting Job Template attribute or values. are any conflicting Job Template attribute or values.
(3) the 'successful-ok-ignored-or-substituted-attributes' status (3) the 'successful-ok-ignored-or-substituted-attributes' status
code, if there are only unsupported Job Template attributes or code, if there are only unsupported Job Template attributes or
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not affect the status returned in this step. If the unsupported not affect the status returned in this step. If the unsupported
Operation attribute was a serious error, the above already rejected the Operation attribute was a serious error, the above already rejected the
request in a previous step. If control gets to this step with request in a previous step. If control gets to this step with
unsupported Operation attributes being returned, they are not serious unsupported Operation attributes being returned, they are not serious
errors. errors.
The Printer object also returns Job status attributes that indicate the The Printer object also returns Job status attributes that indicate the
initial state of the Job ('pending', 'pending-held', 'processing', initial state of the Job ('pending', 'pending-held', 'processing',
etc.), etc. See Print-Job Response, [IPP-MOD] section 3.2.1.2. etc.), etc. See Print-Job Response, [IPP-MOD] section 3.2.1.2.
2.1.2.9 Accept appended Document Content 2.2.3.6 Accept appended Document Content
The Printer object accepts the appended Document Content data and either The Printer object accepts the appended Document Content data and either
starts it printing, or spools it for later processing. starts it printing, or spools it for later processing.
2.1.2.10 Scheduling and Starting to Process the Job 2.2.3.7 Scheduling and Starting to Process the Job
The Printer object uses its own configuration and implementation The Printer object uses its own configuration and implementation
specific algorithms for scheduling the Job in the correct processing specific algorithms for scheduling the Job in the correct processing
order. Once the Printer object begins processing the Job, the Printer order. Once the Printer object begins processing the Job, the Printer
changes the Job's state to 'processing'. If the Printer object supports changes the Job's state to 'processing'. If the Printer object supports
PDL override (the "pdl-override-supported" attribute set to PDL override (the "pdl-override-supported" attribute set to
'attempted'), the implementation does its best to see that IPP 'attempted'), the implementation does its best to see that IPP
attributes take precedence over embedded instructions in the document attributes take precedence over embedded instructions in the document
data. data.
2.1.2.11 Completing the Job 2.2.3.8 Completing the Job
The Printer object continues to process the Job until it can move the The Printer object continues to process the Job until it can move the
Job into the 'completed' state. If an Cancel-Job operation is received, Job into the 'completed' state. If an Cancel-Job operation is received,
the implementation eventually moves the Job into the 'canceled' state. the implementation eventually moves the Job into the 'canceled' state.
If the system encounters errors during processing that do not allow it If the system encounters errors during processing that do not allow it
to progress the Job into a completed state, the implementation halts all to progress the Job into a completed state, the implementation halts all
processing, cleans up any resources, and moves the Job into the processing, cleans up any resources, and moves the Job into the
'aborted' state. 'aborted' state.
Expires May 16, 1999 Expires August 12, 1999
2.1.2.12 Destroying the Job after completion 2.2.3.9 Destroying the Job after completion
Once the Job moves to the 'completed', 'aborted', or 'canceled' state, Once the Job moves to the 'completed', 'aborted', or 'canceled' state,
it is an implementation decision as to when to destroy the Job object it is an implementation decision as to when to destroy the Job object
and release all associated resources. Once the Job has been destroyed, and release all associated resources. Once the Job has been destroyed,
the Printer would return either the "client-error-not-found" or "client- the Printer would return either the "client-error-not-found" or "client-
error-gone" status codes for operations directed at that Job. error-gone" status codes for operations directed at that Job.
Note: the Printer object SHOULD NOT re-use a "job-uri" or "job-id" Note: the Printer object SHOULD NOT re-use a "job-uri" or "job-id"
value for a sufficiently long time after a job has been destroyed, so value for a sufficiently long time after a job has been destroyed, so
that stale references kept by clients are less likely to access the that stale references kept by clients are less likely to access the
wrong (newer) job. wrong (newer) job.
2.1.2.13 Interaction with "ipp-attribute-fidelity" 2.2.3.10 Interaction with "ipp-attribute-fidelity"
Some Printer object implementations may support "ipp-attribute-fidelity" Some Printer object implementations may support "ipp-attribute-fidelity"
set to 'true' and "pdl-override-supported" set to 'attempted' and yet set to 'true' and "pdl-override-supported" set to 'attempted' and yet
still not be able to realize exactly what the client specifies in the still not be able to realize exactly what the client specifies in the
create request. This is due to legacy decisions and assumptions that create request. This is due to legacy decisions and assumptions that
have been made about the role of job instructions embedded within the have been made about the role of job instructions embedded within the
document data and external job instructions that accompany the document document data and external job instructions that accompany the document
data and how to handle conflicts between such instructions. The data and how to handle conflicts between such instructions. The
inability to be 100% precise about how a given implementation will inability to be 100% precise about how a given implementation will
behave is also compounded by the fact that the two special attributes, behave is also compounded by the fact that the two special attributes,
"ipp-attribute-fidelity" and "pdl-override-supported", apply to the "ipp-attribute-fidelity" and "pdl-override-supported", apply to the
whole job rather than specific values for each attribute. For example, whole job rather than specific values for each attribute. For example,
some implementations may be able to override almost all Job Template some implementations may be able to override almost all Job Template
attributes except for "number-up". attributes except for "number-up".
2.2 Status codes returned by operation 2.3 Status codes returned by operation (Issue 1.50)
This section lists all status codes once in the first operation (Print- This section lists all status codes once in the first operation (Print-
Job). Then it lists the status codes that are different or specialized Job). Then it lists the status codes that are different or specialized
for subsequent operations under each operation. for subsequent operations under each operation.
2.2.1Printer Operations 2.3.1Printer Operations
2.2.1.1 Print-Job 2.3.1.1 Print-Job
The Printer object MUST return one of the following "status-code" values The Printer object MUST return one of the following "status-code" values
for the indicated reason. Whether all of the document data has been for the indicated reason. Whether all of the document data has been
accepted or not before returning the success or error response depends accepted or not before returning the success or error response depends
on implementation. See Section 14 for a more complete description of on implementation. See Section 14 for a more complete description of
each status code. each status code.
For the following success status codes, the Job object has been created For the following success status codes, the Job object has been created
and the "job-id", and "job-uri" assigned and returned in the response: and the "job-id", and "job-uri" assigned and returned in the response:
successful-ok: no request attributes were substituted or ignored. successful-ok: no request attributes were substituted or ignored.
successful-ok-ignored-or-substituted-attributes: some supplied (1) successful-ok-ignored-or-substituted-attributes: some supplied (1)
attributes were ignored or (2) unsupported attribute syntaxes or attributes were ignored or (2) unsupported attribute syntaxes or
values were substituted with supported values or were ignored. values were substituted with supported values or were ignored.
Expires May 16, 1999 Expires August 12, 1999
Unsupported attributes, attribute syntaxes, or values MUST be Unsupported attributes, attribute syntaxes, or values MUST be
returned in the Unsupported Attributes group of the response. returned in the Unsupported Attributes group of the response.
successful-ok-conflicting-attributes: some supplied attribute values successful-ok-conflicting-attributes: some supplied attribute values
conflicted with the values of other supplied attributes and were conflicted with the values of other supplied attributes and were
either substituted or ignored. Attributes or values which conflict either substituted or ignored. Attributes or values which conflict
with other attributes and have been substituted or ignored MUST be with other attributes and have been substituted or ignored MUST be
returned in the Unsupported Attributes group of the response as returned in the Unsupported Attributes group of the response as
supplied by the client. supplied by the client.
[ipp-mod] section 3.1.6 Operation Status Codes and Messages states
(Issue 1.19):
If the Printer object supports the "status-message" operation
attribute, it SHOULD use the REQUIRED 'utf-8' charset to return a
status message for the following error status codes (see section
14): 'client-error-bad-request', 'client-error-charset-not-
supported', 'server-error-internal-error', 'server-error-operation-
not-supported', and 'server-error-version-not-supported'. In this
case, it MUST set the value of the "attributes-charset" operation
attribute to 'utf-8' in the error response.
For the following error status codes, no job is created and no "job-id" For the following error status codes, no job is created and no "job-id"
or "job-uri" is returned: or "job-uri" is returned:
client-error-bad-request: The request syntax does not conform to the client-error-bad-request: The request syntax does not conform to the
specification. The IPP object SHOULD NOT return the "status- specification.
message" operation attributes, if supported, if the "attributes-
charset" in the request has not been processed.
client-error-forbidden: The request is being refused for client-error-forbidden: The request is being refused for
authorization or authentication reasons. The implementation authorization or authentication reasons. The implementation
security policy is to not reveal whether the failure is one of security policy is to not reveal whether the failure is one of
authentication or authorization. authentication or authorization.
client-error-not-authenticated: Either the request requires client-error-not-authenticated: Either the request requires
authentication information to be supplied or the authentication authentication information to be supplied or the authentication
information is not sufficient for authorization. information is not sufficient for authorization.
client-error-not-authorized: The requester is not authorized to client-error-not-authorized: The requester is not authorized to
perform the request on the target object. perform the request on the target object.
client-error-not-possible: The request cannot be carried out because client-error-not-possible: The request cannot be carried out because
skipping to change at page 30, line 50 skipping to change at page 36, line 4
and/or print data exceeds the capacity of the IPP Printer to and/or print data exceeds the capacity of the IPP Printer to
process it. process it.
client-error-request-value-too-long: the size of request variable client-error-request-value-too-long: the size of request variable
length attribute values, such as 'text' and 'name' attribute length attribute values, such as 'text' and 'name' attribute
syntaxes, exceed the maximum length specified in [IPP-MOD] for the syntaxes, exceed the maximum length specified in [IPP-MOD] for the
attribute and MUST be returned in the Unsupported Attributes Group. attribute and MUST be returned in the Unsupported Attributes Group.
client-error-document-format-not-supported: the document format client-error-document-format-not-supported: the document format
supplied is not supported. The "document-format" attribute with supplied is not supported. The "document-format" attribute with
the unsupported value MUST be returned in the Unsupported the unsupported value MUST be returned in the Unsupported
Attributes Group. This error SHOULD take precedence over any other Attributes Group. This error SHOULD take precedence over any other
Expires August 12, 1999
'xxx-not-supported' error, except 'client-error-charset-not- 'xxx-not-supported' error, except 'client-error-charset-not-
supported'. supported'.
client-error-attributes-or-values-not-supported: one or more client-error-attributes-or-values-not-supported: one or more
supplied attributes, attribute syntaxes, or values are not supplied attributes, attribute syntaxes, or values are not
supported and the client supplied the "ipp-attributes-fidelity" supported and the client supplied the "ipp-attributes-fidelity"
operation attribute with a 'true' value. They MUST be returned in operation attribute with a 'true' value. They MUST be returned in
the Unsupported Attributes Group as explained below. the Unsupported Attributes Group as explained below.
client-error-uri-scheme-not-supported: not applicable. client-error-uri-scheme-not-supported: not applicable.
client-error-charset-not-supported: the charset supplied in the client-error-charset-not-supported: the charset supplied in the
"attributes-charset" operation attribute is not supported. The "attributes-charset" operation attribute is not supported. The
Expires May 16, 1999
Printer's "configured-charset" MUST be returned in the response as Printer's "configured-charset" MUST be returned in the response as
the value of the "attributes-charset" operation attribute and used the value of the "attributes-charset" operation attribute and used
for any 'text' and 'name' attributes returned in the error for any 'text' and 'name' attributes returned in the error
response. This error SHOULD take precedence over any other error, response. This error SHOULD take precedence over any other error,
unless the request syntax is so bad that the client's supplied unless the request syntax is so bad that the client's supplied
"attributes-charset" cannot be determined. "attributes-charset" cannot be determined.
client-error-conflicting-attributes: one or more supplied attribute client-error-conflicting-attributes: one or more supplied attribute
values conflicted with each other and the client supplied the "ipp- values conflicted with each other and the client supplied the "ipp-
attributes-fidelity" operation attribute with a 'true' value. They attributes-fidelity" operation attribute with a 'true' value. They
MUST be returned in the Unsupported Attributes Group as explained MUST be returned in the Unsupported Attributes Group as explained
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server-error-temporary-error: a temporary error such as a buffer server-error-temporary-error: a temporary error such as a buffer
full write error, a memory overflow, or a disk full condition full write error, a memory overflow, or a disk full condition
occurred while receiving the request and/or the document data. occurred while receiving the request and/or the document data.
server-error-not-accepting-jobs: the Printer object's "printer-is- server-error-not-accepting-jobs: the Printer object's "printer-is-
not-accepting-jobs" attribute is 'false'. not-accepting-jobs" attribute is 'false'.
server-error-busy: the Printer is too busy processing jobs to accept server-error-busy: the Printer is too busy processing jobs to accept
another job at this time. another job at this time.
server-error-job-canceled: the job has been canceled by an operator server-error-job-canceled: the job has been canceled by an operator
or the system while the client was transmitting the document data. or the system while the client was transmitting the document data.
2.2.1.2 Print-URI 2.3.1.2 Print-URI
All of the Print-Job status codes described in Section 3.2.1.2 Print-Job All of the Print-Job status codes described in Section 3.2.1.2 Print-Job
Response are applicable to Print-URI with the following specializations Response are applicable to Print-URI with the following specializations
and differences. See Section 14 for a more complete description of each and differences. See Section 14 for a more complete description of each
status code. status code.
server-error-uri-scheme-not-supported: the URI scheme supplied in server-error-uri-scheme-not-supported: the URI scheme supplied in
the "document-uri" operation attribute is not supported and is the "document-uri" operation attribute is not supported and is
returned in the Unsupported Attributes group. returned in the Unsupported Attributes group.
2.2.1.3 Validate-Job Expires August 12, 1999
2.3.1.3 Validate-Job
All of the Print-Job status codes described in Section 3.2.1.2 Print-Job All of the Print-Job status codes described in Section 3.2.1.2 Print-Job
Response are applicable to Validate-Job. See Section 14 for a more Response are applicable to Validate-Job. See Section 14 for a more
complete description of each status code. complete description of each status code.
2.2.1.4 Create-Job 2.3.1.4 Create-Job
All of the Print-Job status codes described in Section 3.2.1.2 Print-Job All of the Print-Job status codes described in Section 3.2.1.2 Print-Job
Response are applicable to Create-Job with the following specializations Response are applicable to Create-Job with the following specializations
Expires May 16, 1999
and differences. See Section 14 for a more complete description of each and differences. See Section 14 for a more complete description of each
status code. status code.
server-error-operation-not-supported: the Create-Job operation is server-error-operation-not-supported: the Create-Job operation is
not supported. not supported.
2.2.1.5 Get-Printer-Attributes 2.3.1.5 Get-Printer-Attributes
All of the Print-Job status codes described in Section 3.2.1.2 Print-Job All of the Print-Job status codes described in Section 3.2.1.2 Print-Job
Response are applicable to the Get-Printer-Attributes operation with the Response are applicable to the Get-Printer-Attributes operation with the
following specializations and differences. See Section 14 for a more following specializations and differences. See Section 14 for a more
complete description of each status code. complete description of each status code.
For the following success status codes, the requested attributes are For the following success status codes, the requested attributes are
returned in Group 3 in the response: returned in Group 3 in the response:
successful-ok: no request attributes were substituted or ignored successful-ok: no request attributes were substituted or ignored
skipping to change at page 32, line 52 skipping to change at page 38, line 5
Printer-Attributes is REQUIRED). Printer-Attributes is REQUIRED).
server-error-device-error: same as Print-Job, except that no server-error-device-error: same as Print-Job, except that no
document data is involved. document data is involved.
server-error-temporary-error: same as Print-Job, except that no server-error-temporary-error: same as Print-Job, except that no
document data is involved. document data is involved.
server-error-not-accepting-jobs: not applicable.. server-error-not-accepting-jobs: not applicable..
server-error-busy: same as Print-Job, except the IPP object is too server-error-busy: same as Print-Job, except the IPP object is too
busy to accept even query requests. busy to accept even query requests.
server-error-job-canceled: not applicable.. server-error-job-canceled: not applicable..
2.2.1.6 Get-Jobs Expires August 12, 1999
2.3.1.6 Get-Jobs
All of the Print-Job status codes described in Section 3.2.1.2 Print-Job All of the Print-Job status codes described in Section 3.2.1.2 Print-Job
Response are applicable to the Get-Jobs operation with the following Response are applicable to the Get-Jobs operation with the following
specializations and differences. See Section 14 for a more complete specializations and differences. See Section 14 for a more complete
description of each status code. description of each status code.
For the following success status codes, the requested attributes are For the following success status codes, the requested attributes are
returned in Group 3 in the response: returned in Group 3 in the response:
Expires May 16, 1999
successful-ok: no request attributes were substituted or ignored successful-ok: no request attributes were substituted or ignored
(same as Print-Job) and no requested attributes were unsupported. (same as Print-Job) and no requested attributes were unsupported.
successful-ok-ignored-or-substituted-attributes: same as Print-Job, successful-ok-ignored-or-substituted-attributes: same as Print-Job,
except the "requested-attributes" operation attribute MAY, but NEED except the "requested-attributes" operation attribute MAY, but NEED
NOT, be returned with the unsupported values. NOT, be returned with the unsupported values.
successful-ok-conflicting-attributes: same as Print-Job. successful-ok-conflicting-attributes: same as Print-Job.
For any error status codes, Group 3 is returned containing no attributes For any error status codes, Group 3 is returned containing no attributes
or is not returned at all. The following brief error status code or is not returned at all. The following brief error status code
descriptions contain unique information for use with Get-Jobs operation. descriptions contain unique information for use with Get-Jobs operation.
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"ipp-attribute-fidelity" is not involved. "ipp-attribute-fidelity" is not involved.
server-error-operation-not-supported: not applicable (since Get-Jobs server-error-operation-not-supported: not applicable (since Get-Jobs
is REQUIRED). is REQUIRED).
server-error-device-error: same as Print-Job, except that no server-error-device-error: same as Print-Job, except that no
document data is involved. document data is involved.
server-error-temporary-error: same as Print-Job, except that no server-error-temporary-error: same as Print-Job, except that no
document data is involved. document data is involved.
server-error-not-accepting-jobs: not applicable. server-error-not-accepting-jobs: not applicable.
server-error-job-canceled: not applicable. server-error-job-canceled: not applicable.
2.2.2Job Operations 2.3.2Job Operations
2.2.2.1 Send-Document 2.3.2.1 Send-Document
All of the Print-Job status codes described in Section 3.2.1.2 Print-Job All of the Print-Job status codes described in Section 3.2.1.2 Print-Job
Response are applicable to the Get-Printer-Attributes operation with the Response are applicable to the Get-Printer-Attributes operation with the
following specializations and differences. See Section 14 for a more following specializations and differences. See Section 14 for a more
complete description of each status code. complete description of each status code.
For the following success status codes, the document has been added to For the following success status codes, the document has been added to
the specified Job object and the job's "number-of-documents" attribute the specified Job object and the job's "number-of-documents" attribute
has been incremented: has been incremented:
Expires August 12, 1999
successful-ok: no request attributes were substituted or ignored successful-ok: no request attributes were substituted or ignored
(same as Print-Job). (same as Print-Job).
successful-ok-ignored-or-substituted-attributes: same as Print-Job. successful-ok-ignored-or-substituted-attributes: same as Print-Job.
successful-ok-conflicting-attributes: same as Print-Job. successful-ok-conflicting-attributes: same as Print-Job.
For the error status codes, no document has been added to the Job object For the error status codes, no document has been added to the Job object
and the job's "number-of-documents" attribute has not been incremented: and the job's "number-of-documents" attribute has not been incremented:
client-error-not-possible: Same as Print-Job, except that the client-error-not-possible: Same as Print-Job, except that the
Printer's "printer-is-accepting-jobs" attribute is not involved, so Printer's "printer-is-accepting-jobs" attribute is not involved, so
that the client is able to finish submitting a multi-document job that the client is able to finish submitting a multi-document job
Expires May 16, 1999
after this attribute has been set to 'true'. Another condition is after this attribute has been set to 'true'. Another condition is
that the state of the job precludes Send-Document, i.e., the job that the state of the job precludes Send-Document, i.e., the job
has already been closed out by the client. However, if the IPP has already been closed out by the client. However, if the IPP
Printer closed out the job due to timeout, the 'client-error- Printer closed out the job due to timeout, the 'client-error-
timeout' error status SHOULD be returned instead. timeout' error status SHOULD be returned instead.
client-error-timeout: This request was sent after the Printer closed client-error-timeout: This request was sent after the Printer closed
the job, because it has not received a Send-Document or Send-URI the job, because it has not received a Send-Document or Send-URI
operation within the Printer's "multiple-operation-time-out" period operation within the Printer's "multiple-operation-time-out" period
. .
client-error-request-entity-too-large: same as Print-Job. client-error-request-entity-too-large: same as Print-Job.
client-error-conflicting-attributes: same as Print-Job, except that client-error-conflicting-attributes: same as Print-Job, except that
"ipp-attributes-fidelity" operation attribute is not involved.. "ipp-attributes-fidelity" operation attribute is not involved..
server-error-operation-not-supported: the Send-Document request is server-error-operation-not-supported: the Send-Document request is
not supported. not supported.
server-error-not-accepting-jobs: not applicable. server-error-not-accepting-jobs: not applicable.
server-error-job-canceled: the job has been canceled by an operator server-error-job-canceled: the job has been canceled by an operator
or the system while the client was transmitting the data. or the system while the client was transmitting the data.
2.2.2.2 Send-URI 2.3.2.2 Send-URI
All of the Print-Job status code descriptions in Section 3.2.1.2 Print- All of the Print-Job status code descriptions in Section 3.2.1.2 Print-
Job Response with the specializations described for Send-Document are Job Response with the specializations described for Send-Document are
applicable to Send-URI. See Section 14 for a more complete description applicable to Send-URI. See Section 14 for a more complete description
of each status code. of each status code.
server-error-uri-scheme-not-supported: the URI scheme supplied in server-error-uri-scheme-not-supported: the URI scheme supplied in
the "document-uri" operation attribute is not supported and the the "document-uri" operation attribute is not supported and the
"document-uri" attribute MUST be returned in the Unsupported "document-uri" attribute MUST be returned in the Unsupported
Attributes group. Attributes group.
2.2.2.3 Cancel-Job 2.3.2.3 Cancel-Job
All of the Print-Job status codes described in Section 3.2.1.2 Print-Job All of the Print-Job status codes described in Section 3.2.1.2 Print-Job
Response are applicable to Cancel-Job with the following specializations Response are applicable to Cancel-Job with the following specializations
and differences. See Section 14 for a more complete description of each and differences. See Section 14 for a more complete description of each
status code. status code.
For the following success status codes, the Job object is being canceled For the following success status codes, the Job object is being canceled
or has been canceled: or has been canceled:
successful-ok: no request attributes were substituted or ignored successful-ok: no request attributes were substituted or ignored
(same as Print-Job). (same as Print-Job).
successful-ok-ignored-or-substituted-attributes: same as Print-Job. successful-ok-ignored-or-substituted-attributes: same as Print-Job.
successful-ok-conflicting-attributes: same as Print-Job. successful-ok-conflicting-attributes: same as Print-Job.
Expires August 12, 1999
For any of the error status codes, the Job object has not been canceled For any of the error status codes, the Job object has not been canceled
or was previously canceled. or was previously canceled.
client-error-not-possible: The request cannot be carried out because client-error-not-possible: The request cannot be carried out because
of the state of the Job object ('completed', 'canceled', or of the state of the Job object ('completed', 'canceled', or
'aborted') or the state of the system. 'aborted') or the state of the system.
client-error-not-found: the target Printer and/or Job object does client-error-not-found: the target Printer and/or Job object does
not exist. not exist.
client-error-gone: the target Printer and/or Job object no longer client-error-gone: the target Printer and/or Job object no longer
exists and no forwarding address is known. exists and no forwarding address is known.
Expires May 16, 1999
client-error-request-entity-too-large: same as Print-Job, except no client-error-request-entity-too-large: same as Print-Job, except no
document data is involved. document data is involved.
client-error-document-format-not-supported: not applicable. client-error-document-format-not-supported: not applicable.
client-error-attributes-or-values-not-supported: not applicable, client-error-attributes-or-values-not-supported: not applicable,
since unsupported operation attributes and values MUST be ignored. since unsupported operation attributes and values MUST be ignored.
client-error-conflicting-attributes: same as Print-Job, except that client-error-conflicting-attributes: same as Print-Job, except that
the Printer's "printer-is-accepting-jobs" attribute is not the Printer's "printer-is-accepting-jobs" attribute is not
involved. involved.
server-error-operation-not-supported: not applicable (Cancel-Job is server-error-operation-not-supported: not applicable (Cancel-Job is
REQUIRED). REQUIRED).
server-error-device-error: same as Print-Job, except no document server-error-device-error: same as Print-Job, except no document
data is involved. data is involved.
server-error-temporary-error: same as Print-Job, except no document server-error-temporary-error: same as Print-Job, except no document
data is involved. data is involved.
server-error-not-accepting-jobs: not applicable.. server-error-not-accepting-jobs: not applicable..
server-error-job-canceled: not applicable. server-error-job-canceled: not applicable.
2.2.2.4 Get-Job-Attributes 2.3.2.4 Get-Job-Attributes
All of the Print-Job status codes described in Section 3.2.1.2 Print-Job All of the Print-Job status codes described in Section 3.2.1.2 Print-Job
Response are applicable to Get-Job-Attributes with the following Response are applicable to Get-Job-Attributes with the following
specializations and differences. See Section 14 for a more complete specializations and differences. See Section 14 for a more complete
description of each status code. description of each status code.
For the following success status codes, the requested attributes are For the following success status codes, the requested attributes are
returned in Group 3 in the response: returned in Group 3 in the response:
successful-ok: no request attributes were substituted or ignored successful-ok: no request attributes were substituted or ignored
skipping to change at page 35, line 52 skipping to change at page 41, line 4
or is not returned at all. or is not returned at all.
client-error-not-possible: Same as Print-Job, in addition the client-error-not-possible: Same as Print-Job, in addition the
Printer object is not accepting any requests. Printer object is not accepting any requests.
client-error-document-format-not-supported: not applicable. client-error-document-format-not-supported: not applicable.
client-error-attributes-or-values-not-supported: not applicable. client-error-attributes-or-values-not-supported: not applicable.
client-error-uri-scheme-not-supported: not applicable. client-error-uri-scheme-not-supported: not applicable.
client-error-conflicting-attributes: not applicable client-error-conflicting-attributes: not applicable
server-error-operation-not-supported: not applicable (since Get-Job- server-error-operation-not-supported: not applicable (since Get-Job-
Attributes is REQUIRED). Attributes is REQUIRED).
Expires August 12, 1999
server-error-device-error: same as Print-Job, except no document server-error-device-error: same as Print-Job, except no document
data is involved. data is involved.
server-error-temporary-error: sane as Print-Job, except no document server-error-temporary-error: sane as Print-Job, except no document
data is involved.. data is involved..
server-error-not-accepting-jobs: not applicable. server-error-not-accepting-jobs: not applicable.
server-error-job-canceled: not applicable. server-error-job-canceled: not applicable.
Expires May 16, 1999 2.4 Validate-Job
2.3 Validate-Job
The Validate-Job operation has been designed so that its implementation The Validate-Job operation has been designed so that its implementation
may be a part of the Print-Job operation. Therefore, requiring may be a part of the Print-Job operation. Therefore, requiring
Validate-Job is not a burden on implementers. Also it is useful for Validate-Job is not a burden on implementers. Also it is useful for
client's to be able to count on its presence in all conformance client's to be able to count on its presence in all conformance
implementations, so that the client can determine before sending a long implementations, so that the client can determine before sending a long
document, whether the job will be accepted by the IPP Printer or not. document, whether the job will be accepted by the IPP Printer or not.
2.4 Case Sensitivity in URIs 2.5 Case Sensitivity in URIs (issue 1.6)
IPP client and server implementations must be aware of the diverse IPP client and server implementations must be aware of the diverse
uppercase/lowercase nature of URIs. RFC 2396 defines URL schemes and uppercase/lowercase nature of URIs. RFC 2396 defines URL schemes and
Host names as case insensitive but reminds us that the rest of the URL Host names as case insensitive but reminds us that the rest of the URL
may well demonstrate case sensitivity. When creating URL's for fields may well demonstrate case sensitivity. When creating URL's for fields
where the choice is completely arbitrary, it is probably best to select where the choice is completely arbitrary, it is probably best to select
lower case. However, this cannot be guaranteed and implementations MUST lower case. However, this cannot be guaranteed and implementations MUST
NOT rely on any fields being case-sensitive or case-insensitive in the NOT rely on any fields being case-sensitive or case-insensitive in the
URL beyond the URL scheme and host name fields. URL beyond the URL scheme and host name fields.
The reason that the IPP specification does not make any restrictions on The reason that the IPP specification does not make any restrictions on
URIs, is so that implementations of IPP may use off-the-shelf components URIs, is so that implementations of IPP may use off-the-shelf components
that conform to the standards that define URIs, such as RFC 2396 and the that conform to the standards that define URIs, such as RFC 2396 and the
HTTP/1.1 specifications [RFC2068]. See these specifications for rules HTTP/1.1 specifications [RFC2068]. See these specifications for rules
of matching, comparison, and case-sensitivity. of matching, comparison, and case-sensitivity.
It is also recommended that that System Administrators and It is also recommended that System Administrators and implementations
implementations avoid creating URLs for different printers that differ avoid creating URLs for different printers that differ only in their
only in their case. For example, don't have Printer1 and printer1 as case. For example, don't have Printer1 and printer1 as two different
two different IPP Printers. IPP Printers.
The HTTP/1.1 specification [RFC2068] contains more details on comparing The HTTP/1.1 specification [RFC2068] contains more details on comparing
URLs. URLs.
2.5 Natural Language Override (NLO) 2.6 Character Sets, natural languages, and internationalization
This section discusses character set support, natural language support
and internationalization.
2.6.1Character set code conversion support (Issue 1.5)
IPP clients and IPP objects are REQUIRED to support UTF-8. They MAY
support additional charsets. It is RECOMMENDED that an IPP object also
support US-ASCII, since many clients support US-ASCII, and indicate that
Expires August 12, 1999
UTF-8 and US-ASCII are supported by populating the Printer's "charset-
supported" with 'utf-8' and 'us-ascii' values. An IPP object is
required to code covert with as little loss as possible between the
charsets that it supports, as indicated in the Printer's "charsets-
supported" attribute.
How should the server handle the situation where the "attributes-
charset" of the response itself is "us-ascii", but one or more
attributes in that response is in the "utf-8" format?
Example: Consider a case where a client sends a Print-Job request with
"utf-8" as the value of "attributes-charset" and with the "job-name"
attribute supplied. Later another client submits a Get-Job-Attribute or
Get-Jobs request. This second request contains the "attributes-charset"
with value "us-ascii" and "requested-attributes" attribute with exactly
one value "job-name".
According to the IPP-Mod document (section 3.1.4.2), the value of the
"attributes-charset" for the response of the second request must be "us-
ascii" since that is the charset specified in the request. The "job-
name" value, however, is in "utf-8" format. Should the request be
rejected even though both "utf-8" and "us-ascii" charsets are supported
by the server? or should the "job-name" value be converted to "us-ascii"
and return "successful-ok-conflicting-attributes" (0x0002) as the
status code?
Answer: An IPP object that supports both utf-8 (REQUIRED) and us-ascii,
the second paragraph of section 3.1.4.2 applies so that the IPP object
MUST accept the request, perform code set conversion between these two
charsets with "the highest fidelity possible" and return 'successful-
ok', rather than a warning 'successful-ok-conflicting-attributes, or an
error. The printer will do the best it can to convert between each of
the character sets that it supports--even if that means providing a
string of question marks because none of the characters are
representable in US ASCII. If it can't perform such conversion, it MUST
NOT advertise us-ascii as a value of its "attributes-charset-supported"
and MUST reject any request that requests 'us-ascii'.
One IPP object implementation strategy is to convert all request text
and name values to a Unicode internal representation. This is 16-bit
and virtually universal. Then convert to the specified operation
attributes-charset on output.
Also it would be smarter for a client to ask for 'utf-8', rather than
'us-ascii' and throw away characters that it doesn't understand, rather
than depending on the code conversion of the IPP object.
2.6.2What charset to return when an unsupported charset is requested
(Issue 1.19)?
Section 3.1.4.1 Request Operation attributes was clarified in November
1998 as follows:
Expires August 12, 1999
All clients and IPP objects MUST support the 'utf-8' charset
[RFC2044] and MAY support additional charsets provided that they
are registered with IANA [IANA-CS]. If the Printer object does not
support the client supplied charset value, the Printer object MUST
reject the request, set the "attributes-charset" to 'utf-8' in the
response, and return the 'client-error-charset-not-supported'
status code and any 'text' or 'name' attributes using the 'utf-8'
charset.
Since the client and IPP object MUST support UTF-8, returning any text
or name attributes in UTF-8 when the client requests a charset that is
not supported should allow the client to display the text or name.
Since such an error is a client error, rather than a user error, the
client should check the status code first so that it can avoid
displaying any other returned 'text' and 'name' attributes that are not
in the charset requested.
Furthermore, [ipp-mod] section 14.1.4.14 client-error-charset-not-
supported (0x040D) was clarified in November 1998 as follows:
For any operation, if the IPP Printer does not support the charset
supplied by the client in the "attributes-charset" operation
attribute, the Printer MUST reject the operation and return this
status and any 'text' or 'name' attributes using the 'utf-8'
charset (see Section 3.1.4.1).
2.6.3Natural Language Override (NLO) (Issue 1.45)
The 'text' and 'name' attributes each have two forms. One has an The 'text' and 'name' attributes each have two forms. One has an
implicit natural language, and the other has an explicit natural implicit natural language, and the other has an explicit natural
language. The 'textWithoutLanguage' and 'textWithoutLanguage' are the language. The 'textWithoutLanguage' and 'textWithoutLanguage' are the
two 'text' forms. The 'nameWithoutLanguage" and 'nameWithLanguage are two 'text' forms. The 'nameWithoutLanguage" and 'nameWithLanguage are
the two 'name' forms. If a receiver (IPP object or IPP client) supports the two 'name' forms. If a receiver (IPP object or IPP client) supports
an attribute with attribute syntax 'text', it MUST support both forms in an attribute with attribute syntax 'text', it MUST support both forms in
a request and a response. A sender (IPP client or IPP object) MAY send a request and a response. A sender (IPP client or IPP object) MAY send
either form for any such attribute. When a sender sends a either form for any such attribute. When a sender sends a
WithoutLanguage form, the implicit natural language is specified in the WithoutLanguage form, the implicit natural language is specified in the
"attributes-natural-language" operation attribute which all senders MUST "attributes-natural-language" operation attribute which all senders MUST
include in every request and response. include in every request and response.
When a sender sends a WithLanguage form, it MAY be different from the When a sender sends a WithLanguage form, it MAY be different from the
implicit natural language supplied by the sender or it MAY be the same. implicit natural language supplied by the sender or it MAY be the same.
The receiver MUST treat either form equivalently. The receiver MUST treat either form equivalently.
Expires May 16, 1999
There is an implementation decision for senders, whether to always send There is an implementation decision for senders, whether to always send
the WithLanguage forms or use the WithoutLanguage form when the the WithLanguage forms or use the WithoutLanguage form when the
attribute's natural language is the same as the request or response. attribute's natural language is the same as the request or response.
The former approach makes the sender implementation simpler. The latter The former approach makes the sender implementation simpler. The latter
approach is more efficient on the wire and allows inter-working with approach is more efficient on the wire and allows inter-working with
non-conforming receivers that fail to support the WithLanguage forms. non-conforming receivers that fail to support the WithLanguage forms.
As each approach have advantages, the choice is completely up to the As each approach have advantages, the choice is completely up to the
implementer of the sender. implementer of the sender.
Expires August 12, 1999
Furthermore, when a client receives a 'text' or 'name' job attribute Furthermore, when a client receives a 'text' or 'name' job attribute
that it had previously supplied, that client MUST NOT expect to see the that it had previously supplied, that client MUST NOT expect to see the
attribute in the same form, i.e., in the same WithoutLanguage or attribute in the same form, i.e., in the same WithoutLanguage or
WithLanguage form as the client supplied when it created the job. The WithLanguage form as the client supplied when it created the job. The
IPP object is free to transform the attribute from the WithLanguage form IPP object is free to transform the attribute from the WithLanguage form
to the WithoutLanguage form and vice versa, as long as the natural to the WithoutLanguage form and vice versa, as long as the natural
language is preserved. However, in order to meet this latter language is preserved. However, in order to meet this latter
requirement, it is usually simpler for the IPP object implementation to requirement, it is usually simpler for the IPP object implementation to
store the natural language explicitly with the attribute value, i.e., to store the natural language explicitly with the attribute value, i.e., to
store using an internal representation that resembles the WithLanguage store using an internal representation that resembles the WithLanguage
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(unrequested) Job Attribute which then specified the implicit natural (unrequested) Job Attribute which then specified the implicit natural
language for any other WithoutLanguage job attributes returned in the language for any other WithoutLanguage job attributes returned in the
response for that job. Interoperability testing of early response for that job. Interoperability testing of early
implementations showed that no one was implementing the job-level NLO in implementations showed that no one was implementing the job-level NLO in
Get-Job responses. So the job-level NLO was eliminated from the Get- Get-Job responses. So the job-level NLO was eliminated from the Get-
Jobs response. This simplification makes all requests and responses Jobs response. This simplification makes all requests and responses
consistent in that the implicit natural language for any WithoutLanguage consistent in that the implicit natural language for any WithoutLanguage
'text' or 'name' form is always supplied in the request's or response's 'text' or 'name' form is always supplied in the request's or response's
"attributes-natural-language" operation attribute. "attributes-natural-language" operation attribute.
Expires May 16, 1999 2.7 The "queued-job-count" Printer Description attribute
2.6 The "queued-job-count" Printer Description attribute
2.6.1Why is "queued-job-count" RECOMMENDED? 2.7.1Why is "queued-job-count" RECOMMENDED (Issue 1.14)?
The reason that "queued-job-count" is RECOMMENDED, is that some clients The reason that "queued-job-count" is RECOMMENDED, is that some clients
look at that attribute alone when summarizing the status of a list of look at that attribute alone when summarizing the status of a list of
printers, instead of doing a Get-Jobs to determine the number of jobs in printers, instead of doing a Get-Jobs to determine the number of jobs in
the queue. Implementations that fail to support the "queued-job-count" the queue. Implementations that fail to support the "queued-job-count"
Expires August 12, 1999
will cause that client to display 0 jobs when there are actually queued will cause that client to display 0 jobs when there are actually queued
jobs. jobs.
We would have made it a REQUIRED Printer attribute, but some We would have made it a REQUIRED Printer attribute, but some
implementations had already been completed before the issue was raised, implementations had already been completed before the issue was raised,
so making it a SHOULD was a compromise. so making it a SHOULD was a compromise.
2.6.2Is "queued-job-count" a good measure of how busy a printer is? 2.7.2Is "queued-job-count" a good measure of how busy a printer is
(Issue 1.15)?
The "queued-job-count" is not a good measure of how busy the printer is The "queued-job-count" is not a good measure of how busy the printer is
when there are held jobs. A future registration could be to add a when there are held jobs. A future registration could be to add a
"held-job-count" (or an "active-job-count") Printer Description "held-job-count" (or an "active-job-count") Printer Description
attribute if experience shows that such an attribute (combination) is attribute if experience shows that such an attribute (combination) is
needed to quickly indicate how busy a printer really is. needed to quickly indicate how busy a printer really is.
2.7 Sending empty attribute groups 2.8 Sending empty attribute groups (Issue 1.16)
The [IPP-MOD] and [IPP-PRO] specifications RECOMMEND that a sender not The [IPP-MOD] and [IPP-PRO] specifications RECOMMEND that a sender not
send an empty attribute group in a request or a response. However, they send an empty attribute group in a request or a response. However, they
REQUIRE a receiver to accept an empty attribute group as equivalent to REQUIRE a receiver to accept an empty attribute group as equivalent to
the omission of that group. So a client SHOULD omit the Job Template the omission of that group. So a client SHOULD omit the Job Template
Attributes group entirely in a create operation that is not supplying Attributes group entirely in a create operation that is not supplying
any Job Template attributes. Similarly, an IPP object SHOULD omit an any Job Template attributes. Similarly, an IPP object SHOULD omit an
empty Unsupported Attributes group if there are no unsupported empty Unsupported Attributes group if there are no unsupported
attributes to be returned in a response. attributes to be returned in a response.
2.8 Returning unsupported attributes in Get-Xxxx responses The [IPP-PRO] specification REQUIRES a receiver to be able to receive
either an empty attribute group or an omitted attribute group and treat
them equivalently. The term "receiver" means an IPP object for a
request and a client for a response. The term "sender' means a client
for a request and an IPP object for a response.
The client cannot depend on getting unsupported attributes returned in There is an exception to the rule for Get-Jobs when there are no
the Unsupported Attributes group of Get-Printer-Attributes, Get-Jobs, or attributes to be returned. [ipp-pro] contains the following paragraph:
Get-Job-Attributes responses that the client requested, but are not
supported by the IPP object. However, such unsupported requested
attributes will not be returned in the Job Attributes or Printer
Attributes group (since they are unsupported). However, the IPP object
is REQUIRED to return the 'successful-ok-ignored-or-substituted-
attributes' status code, so that the client know that all that was
requested has not been returned.
2.9 Returning job-state in Print-Job response The syntax allows an xxx-attributes-tag to be present when the xxx-
attribute-sequence that follows is empty. The syntax is defined
this way to allow for the response of Get-Jobs where no attributes
are returned for some job-objects. Although it is RECOMMENDED that
the sender not send an xxx-attributes-tag if there are no
attributes (except in the Get-Jobs response just mentioned), the
receiver MUST be able to decode such syntax.
2.9 Returning unsupported attributes in Get-Xxxx responses (Issue 1.18)
In the Get-Printer-Attributes, Get-Jobs, or Get-Job-Attributes
responses, the client cannot depend on getting unsupported attributes
returned in the Unsupported Attributes group that the client requested,
but are not supported by the IPP object. However, such unsupported
requested attributes will not be returned in the Job Attributes or
Expires August 12, 1999
Printer Attributes group (since they are unsupported). Furthermore, the
IPP object is REQUIRED to return the 'successful-ok-ignored-or-
substituted-attributes' status code, so that the client knows that not
all that was requested has been returned.
2.10Returning job-state in Print-Job response (Issue 1.30)
An IPP client submits a small job via Print-Job. By the time the IPP An IPP client submits a small job via Print-Job. By the time the IPP
printer/print server is putting together a response to the operation, printer/print server is putting together a response to the operation,
Expires May 16, 1999
the job has finished printing and been removed as an object from the the job has finished printing and been removed as an object from the
print system. What should the job-state be in the response? print system. What should the job-state be in the response?
The Model suggests that the Printer return a response before it even The Model suggests that the Printer return a response before it even
accepts the document content. The Job Object Attributes are returned accepts the document content. The Job Object Attributes are returned
only if the IPP object returns one of the success status codes. Then the only if the IPP object returns one of the success status codes. Then the
job-state would always be "pending" or "pending-held". job-state would always be "pending" or "pending-held".
This issue comes up for the implementation of an IPP Printer object as a This issue comes up for the implementation of an IPP Printer object as a
server that forwards jobs to devices that do not provide job status back server that forwards jobs to devices that do not provide job status back
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On the other hand, if the server is able to query the device and/or On the other hand, if the server is able to query the device and/or
setup some sort of event notification that the device initiates when the setup some sort of event notification that the device initiates when the
job makes state transitions, then the server can return the current job job makes state transitions, then the server can return the current job
state in the Print-Job response and in subsequent queries because the state in the Print-Job response and in subsequent queries because the
server knows what the job state is in the device (or can query the server knows what the job state is in the device (or can query the
device). device).
All of these alternatives depend on implementation of the server and the All of these alternatives depend on implementation of the server and the
device. device.
2.10Multi-valued attributes 2.11Flow controlling the data portion of a Print-Job request (Issue
1.22)
A paused printer (or one that is stopped due to paper out or jam or
spool space full or buffer space full, may flow control the data of a
Expires August 12, 1999
Print-Job operation (at the TCP/IP layer), so that the client is not
able to send all the document data. Consequently, the Printer will not
return a response until the condition is changed.
The Printer should not return a Print-Job response with an error code in
any of these conditions, since either the printer will be resumed and/or
the condition will be freed either by human intervention or as jobs
print.
In writing test scripts to test IPP Printers, the script must also be
written not to expect a response, if the printer has been paused, until
the printer is resumed, in order to work with all possible
implementations.
2.12Multi-valued attributes (Issue 1.31)
What is the attribute syntax for a multi-valued attribute? Since some What is the attribute syntax for a multi-valued attribute? Since some
attributes support values in more than one data type, such as "media", attributes support values in more than one data type, such as "media",
"job-hold-until", and "job-sheets", IPP semantics associate the "job-hold-until", and "job-sheets", IPP semantics associate the
attribute syntax with each value, not with the attribute as a whole. attribute syntax with each value, not with the attribute as a whole.
The protocol associates the attribute syntax tag with each value. Don't The protocol associates the attribute syntax tag with each value. Don't
be fooled, just because the attribute syntax tag comes before the be fooled, just because the attribute syntax tag comes before the
attribute keyword. All attribute values after the first have a zero attribute keyword. All attribute values after the first have a zero
length attribute keyword as the indication of a subsequent value of the length attribute keyword as the indication of a subsequent value of the
same attribute. same attribute.
Expires May 16, 1999 2.13Querying jobs with IPP that were submitted using other job
submission protocols (Issue 1.32)
The following clarification was added to [ipp-mod] section 8.5:
8.5 Queries on jobs submitted using non-IPP protocols
If the device that an IPP Printer is representing is able to accept
jobs using other job submission protocols in addition to IPP, it is
RECOMMEND that such an implementation at least allow such "foreign"
jobs to be queried using Get-Jobs returning "job-id" and "job-uri"
as 'unknown'. Such an implementation NEED NOT support all of the
same IPP job attributes as for IPP jobs. The IPP object returns
the 'unknown' out-of-band value for any requested attribute of a
foreign job that is supported for IPP jobs, but not for foreign
jobs.
It is further RECOMMENDED, that the IPP Printer generate "job-id"
and "job-uri" values for such "foreign jobs", if possible, so that
they may be targets of other IPP operations, such as Get-Job-
Attributes and Cancel-Job. Such an implementation also needs to
deal with the problem of authentication of such foreign jobs. One
approach would be to treat all such foreign jobs as belonging to
users other than the user of the IPP client. Another approach
would be for the foreign job to belong to 'anonymous'. Only if the
IPP client has been authenticated as an operator or administrator
of the IPP Printer object, could the foreign jobs be queried by an
Expires August 12, 1999
IPP request. Alternatively, if the security policy is to allow
users to query other users' jobs, then the foreign jobs would also
be visible to an end-user IPP client using Get-Jobs and Get-Job-
Attributes.
Thus IPP MAY be implemented as a "universal" protocol that provides
access to jobs submitted with any job submission protocol. As IPP
becomes widely implemented, providing a more universal access makes
sense.
2.14The 'none' value for empty sets (Issue 1.37)
[ipp-mod] states that the 'none' value should be used as the value of a
1SetOf when the set is empty. In most cases, sets that are potentially
empty contain keywords so the keyword 'none' is used, but for the 3
finishings attributes, the values are enums and thus the empty set is
represented by the enum 3. Currently there are no other attributes with
1SetOf values which can be empty and can contain values that are not
keywords. This exception requires special code and is a potential place
for bugs. It would have been better if we had chosen an out-of-band
value, either "no-value" or some new value, such as 'none'. Since we
didn't, implementations have to deal with the different representations
of 'none', depending on the attribute syntax.
2.15Get-Jobs, my-jobs='true', and 'requesting-user-name' (Issue 1.39)?
In [ipp-mod] section 3.2.6.1 'Get-Jobs Request', if the attribute 'my-
jobs' is present and set to TRUE, MUST the 'requesting-user-name'
attribute be there to, and if it's not present what should the IPP
printer do?
[ipp-mod] Section 8.3 describes the various cases of "requesting-user-
name" being present or not for any operation. If the client does not
supply a value for "requesting-user-name", the printer MUST assume that
the client is supplying some anonymous name, such as "anonymous".
2.16The "multiple-document-handling" Job Template attribute and support
of multiple document jobs
ISSUE: IPP/1.0 is silent on which of the four effects an implementation
would perform if it supports Create-Job, but does not support "multiple-
document-handling".
A fix to IPP/1.0 would be to require implementing all four values of
"multiple-document-handling" if Create-Job is supported at all. Or at
least 'single-document-new-sheet' and 'separate-documents-uncollated-
copies'. In any case, an implementation that supports Create-Job SHOULD
also support "multiple-document-handling". Support for all four values
is RECOMMENDED, but at least the 'single-document-new-sheet' and
'separate-documents-uncollated-copies' values, along with the "multiple-
document-handling-default" indicating the default behavior and
Expires August 12, 1999
"multiple-document-handling-supported" values. If an implementation
spools the data, it should also support the 'separate-documents-
collated-copies' value as well.
3 Encoding and Transport 3 Encoding and Transport
This section discusses various aspects of IPP/1.0 Encoding and Transport This section discusses various aspects of IPP/1.0 Encoding and Transport
[IPP-PRO]. [IPP-PRO].
The IPP layer doesn't have to deal with chunking. In the context of CGI A server is not required to send a response until after it has received
scripts, the HTTP layer removes any chunking information in the received the client.s entire request. Hence, a client must not expect a response
data. until after it has sent the entire request. However, we recommend that
the server return a response as soon as possible if an error is detected
A client MUST NOT expect a response from an IPP server until after the while the client is still sending the data, rather than waiting until
client has sent the entire response. But a client MAY listen for an all of the data is received. Therefore, we also recommend that a client
error response that an IPP server MAY send before it receives all the listen for an error response that an IPP server MAY send before it
data. In this case a client, if chunking the data, can send a premature receives all the data. In this case a client, if chunking the data, can
zero-length chunk to end the request before sending all the data. If the send a premature zero-length chunk to end the request before sending all
request is blocked for some reason, a client MAY determine the reason by the data (and so the client can keep the connection open for other
opening another connection to query the server. requests, rather than closing it). If the request is blocked for some
reason, a client MAY determine the reason by opening another connection
to query the server using Get-Printer-Attributes.
In the following sections, there are a tables of all HTTP headers which In the following sections, there are a tables of all HTTP headers which
describe their use in an IPP client or server. The following is an describe their use in an IPP client or server. The following is an
explanation of each column in these tables. explanation of each column in these tables.
@ the "header" column contains the name of a header @ the .header. column contains the name of a header
@ the "request/client" column indicates whether a client sends the @ the .request/client. column indicates whether a client sends the
header. header.
@ the "request/ server" column indicates whether a server supports @ the .request/ server. column indicates whether a server supports
the header when received. the header when received.
@ the "response/ server" column indicates whether a server sends the @ the .response/ server. column indicates whether a server sends the
header. header.
@ the "response /client" column indicates whether a client supports @ the .response /client. column indicates whether a client supports
the header when received. the header when received.
@ the "values and conditions" column specifies the allowed header @ the .values and conditions. column specifies the allowed header
values and the conditions for the header to be present in a values and the conditions for the header to be present in a
request/response. request/response.
The table for "request headers" does not have columns for responses, and The table for .request headers. does not have columns for responses, and
the table for "response headers" does not have columns for requests. the table for .response headers. does not have columns for requests.
The following is an explanation of the values in the "request/client" The following is an explanation of the values in the .request/client.
and "response/ server" columns. and .response/ server. columns.
@ must: the client or server MUST send the header, @ must: the client or server MUST send the header,
@ must-if: the client or server MUST send the header when the @ must-if: the client or server MUST send the header when the
condition described in the "values and conditions" column is met, condition described in the .values and conditions. column is met,
@ may: the client or server MAY send the header @ may: the client or server MAY send the header
@ not: the client or server SHOULD NOT send the header. It is not @ not: the client or server SHOULD NOT send the header. It is not
relevant to an IPP implementation. relevant to an IPP implementation.
The following is an explanation of the values in the "response/client" Expires August 12, 1999
and "request/ server" columns.
The following is an explanation of the values in the .response/client.
and .request/ server. columns.
@ must: the client or server MUST support the header, @ must: the client or server MUST support the header,
@ may: the client or server MAY support the header @ may: the client or server MAY support the header
@ not: the client or server SHOULD NOT support the header. It is not @ not: the client or server SHOULD NOT support the header. It is not
relevant to an IPP implementation. relevant to an IPP implementation.
Expires May 16, 1999
3.1 General Headers 3.1 General Headers
The following is a table for the general headers. The following is a table for the general headers.
General- Request Response Values and Conditions General- Request Response Values and Conditions
Header Header
Client Server Server Client Client Server Server Client
Cache- must not must not "no-cache" only Cache- must not must not .no-cache. only
Control Control
Connection must-if must must- must "close" only. Both Connection must-if must must- must .close. only. Both
if client and server if client and server
SHOULD keep a SHOULD keep a
connection for the connection for the
duration of a sequence duration of a sequence
of operations. The of operations. The
client and server MUST client and server MUST
include this header include this header
for the last operation for the last operation
in such a sequence. in such a sequence.
Date may may must may per RFC 1123 [RFC1123] Date may may must may per RFC 1123 [RFC1123]
from RFC 2068 from RFC 2068
[RFC2068] [RFC2068]
Pragma must not must not "no-cache" only Pragma must not must not .no-cache. only
Transfer- must-if must must- must "chunked" only . Transfer- must-if must must- must .chunked. only .
Encoding if Header MUST be present Encoding if Header MUST be present
if Content-Length is if Content-Length is
absent. absent.
Upgrade not not not not Upgrade not not not not
Via not not not not Via not not not not
3.2 Request Headers 3.2 Request Headers
The following is a table for the request headers. The following is a table for the request headers.
Request-Header Client Server Request Values and Conditions Request-Header Client Server Request Values and Conditions
Accept may must "application/ipp" only. This Accept may must .application/ipp. only. This
value is the default if the value is the default if the
Expires August 12, 1999
Request-Header Client Server Request Values and Conditions
client omits it client omits it
Accept-Charset not not Charset information is within Accept-Charset not not Charset information is within
the application/ipp entity the application/ipp entity
Accept-Encoding may must empty and per RFC 2068 [RFC2068] Accept-Encoding may must empty and per RFC 2068 [RFC2068]
and IANA registry for content- and IANA registry for content-
Expires May 16, 1999
Request-Header Client Server Request Values and Conditions
codings codings
Accept-Language not not language information is within Accept-Language not not language information is within
the application/ipp entity the application/ipp entity
Authorization must-if must per RFC 2068. A client MUST send Authorization must-if must per RFC 2068. A client MUST send
this header when it receives a this header when it receives a
401 "Unauthorized" response and 401 .Unauthorized. response and
does not receive a "Proxy- does not receive a .Proxy-
Authenticate" header. Authenticate. header.
>From not not per RFC 2068. Because RFC >From not not per RFC 2068. Because RFC
recommends sending this header recommends sending this header
only with the user's approval, it only with the user.s approval, it
is not very useful is not very useful
Host must must per RFC 2068 Host must must per RFC 2068
If-Match not not If-Match not not
If-Modified- not not If-Modified- not not
Since Since
If-None-Match not not If-None-Match not not
If-Range not not If-Range not not
If-Unmodified- not not If-Unmodified- not not
Since Since
Max-Forwards not not Max-Forwards not not
Proxy- must-if not per RFC 2068. A client MUST send Proxy- must-if not per RFC 2068. A client MUST send
Authorization this header when it receives a Authorization this header when it receives a
401 "Unauthorized" response and a 401 .Unauthorized. response and a
"Proxy-Authenticate" header. .Proxy-Authenticate. header.
Range not not Range not not
Referer not not Referer not not
User-Agent not not User-Agent not not
Expires August 12, 1999
3.3 Response Headers 3.3 Response Headers
The following is a table for the request headers. The following is a table for the request headers.
Response- Server Client Response Values and Conditions Response- Server Client Response Values and Conditions
Header Header
Expires May 16, 1999
Response- Server Client Response Values and Conditions
Header
Accept-Ranges not not Accept-Ranges not not
Age not not Age not not
Location must-if may per RFC 2068. When URI needs Location must-if may per RFC 2068. When URI needs
redirection. redirection.
Proxy- not must per RFC 2068 Proxy- not must per RFC 2068
Authenticate Authenticate
skipping to change at page 43, line 55 skipping to change at page 53, line 4
Encoding registry for content Encoding registry for content
codings. codings.
Content- not not not not Application/ipp Content- not not not not Application/ipp
Language handles language Language handles language
Content- must-if must must-if must the length of the Content- must-if must must-if must the length of the
Length message-body per RFC Length message-body per RFC
2068. Header MUST be 2068. Header MUST be
present if Transfer- present if Transfer-
Encoding is absent..
Content- not not not not Expires August 12, 1999
Location
Expires May 16, 1999
Entity-Header Request Response Values and Conditions Entity-Header Request Response Values and Conditions
Client Server Server Client Client Server Server Client
Encoding is absent..
Content- not not not not
Location
Content-MD5 may may may may per RFC 2068 Content-MD5 may may may may per RFC 2068
Content-Range not not not not Content-Range not not not not
Content-Type must must must must "application/ipp" Content-Type must must must must .application/ipp.
only only
ETag not not not not ETag not not not not
Expires not not not not Expires not not not not
Last-Modified not not not not Last-Modified not not not not
3.5 Optional support for HTTP/1.0 3.5 Optional support for HTTP/1.0
skipping to change at page 44, line 39 skipping to change at page 53, line 45
all clients and all servers. However, a client and/or a server all clients and all servers. However, a client and/or a server
implementation may choose to also support HTTP 1.0. implementation may choose to also support HTTP 1.0.
@ This option means that a server may choose to communicate with a @ This option means that a server may choose to communicate with a
(non-conforming) client that only supports HTTP 1.0. In such cases (non-conforming) client that only supports HTTP 1.0. In such cases
the server should not use any HTTP 1.1 specific parameters or the server should not use any HTTP 1.1 specific parameters or
features and should respond using HTTP version number 1.0. features and should respond using HTTP version number 1.0.
@ This option also means that a client may choose to communicate with a @ This option also means that a client may choose to communicate with a
(non-conforming) server that only supports HTTP 1.0. In such cases, (non-conforming) server that only supports HTTP 1.0. In such cases,
if the server responds with an HTTP 'unsupported version number' to if the server responds with an HTTP .unsupported version number. to
an HTTP 1.1 request, the client should retry using HTTP version an HTTP 1.1 request, the client should retry using HTTP version
number 1.0. number 1.0.
3.6 HTTP/1.1 Chunking 3.6 HTTP/1.1 Chunking
3.6.1Disabling IPP Server Response Chunking
Clients MUST anticipate that the HTTP/1.1 server may chunk responses and Clients MUST anticipate that the HTTP/1.1 server may chunk responses and
MUST accept them in responses. However, a (non-conforming) HTTP client MUST accept them in responses. However, a (non-conforming) HTTP client
that is unable to accept chunked responses may attempt to request an that is unable to accept chunked responses may attempt to request an
HTTP 1.1 server not to use chunking in its response to an operation by HTTP 1.1 server not to use chunking in its response to an operation by
using the following HTTP header: using the following HTTP header:
Expires August 12, 1999
TE: identity TE: identity
This mechanism should not be used by a server to disable a client from This mechanism should not be used by a server to disable a client from
chunking a request, since chunking of document data is an important chunking a request, since chunking of document data is an important
feature for clients to send long documents. feature for clients to send long documents.
Expires May 16, 1999 3.6.2Warning About the Support of Chunked Requests
This section describes some problems with the use of chunked requests
and HTTP/1.1 servers.
The HTTP/1.1 standard [HTTP] requires that conforming servers support
chunked requests for any method. However, in spite of this requirement,
some HTTP/1.1 implementations support chunked responses in the GET
method, but do not support chunked POST method requests. Some HTTP/1.1
implementations that support CGI scripts [CGI] and/or servlets [Servlet]
require that the client supply a Content-Length. These implementations
might reject a chunked POST method and return a 411 status code (Length
Required), might attempt to buffer the request and run out of room
returning a 413 status code (Request Entity Too Large), or might
successfully accept the chunked request.
Because of this lack of conformance of HTTP servers to the HTTP/1.1
standard, the IPP standard [IPP-PRO] REQUIRES that a conforming IPP
Printer object implementation support chunked requests and that
conforming clients accept chunked responses. Therefore, IPP object
implementers are warned to seek HTTP server implementations that support
chunked POST requests in order to conform to the IPP standard and/or use
implementation techniques that support chunked POST requests.
4 References 4 References
[CGI]
CGI/1.1 (http://www.ietf.org/internet-drafts/draft-coar-cgi-v11-
00.txt).
[HTTP]
HTTP/1.1 (http://www.ietf.org/internet-drafts/draft-ietf-http-v11-
spec-rev-06.txt)
[IPP LPD] [IPP LPD]
Herriot, R., Hastings, T., Jacobs, N., Martin, J., "Mapping between Herriot, R., Hastings, T., Jacobs, N., Martin, J., "Mapping between
LPD and IPP Protocols", draft-ietf-ipp-lpd-ipp-map-04.txt, June LPD and IPP Protocols", draft-ietf-ipp-lpd-ipp-map-04.txt, June
1998. 1998.
[IPP-MOD] [IPP-MOD]
R. deBry, T. Hastings, R. Herriot, S. Isaacson, P. Powell, R. deBry, T. Hastings, R. Herriot, S. Isaacson, P. Powell,
"Internet Printing Protocol/1.0: Model and Semantics", draft-ietf- "Internet Printing Protocol/1.0: Model and Semantics", draft-ietf-
ipp-model-11.txt, November, 1998. ipp-model-11.txt, November, 1998.
Expires August 12, 1999
[IPP-PRO] [IPP-PRO]
Herriot, R., Butler, S., Moore, P., Tuner, R., "Internet Printing Herriot, R., Butler, S., Moore, P., Tuner, R., "Internet Printing
Protocol/1.0: Encoding and Transport", draft-ietf-ipp-pro-06.txt, Protocol/1.0: Encoding and Transport", draft-ietf-ipp-protocol-
June, 1998. 07.txt, November, 1998.
[IPP-RAT] [IPP-RAT]
Zilles, S., "Rationale for the Structure and Model and Protocol for Zilles, S., "Rationale for the Structure and Model and Protocol for
the Internet Printing Protocol", draft-ietf-ipp-rat-03.txt, June, the Internet Printing Protocol", draft-ietf-ipp-rat-03.txt, June,
1998. 1998.
[IPP-REQ] [IPP-REQ]
Wright, D., "Design Goals for an Internet Printing Protocol", Wright, D., "Design Goals for an Internet Printing Protocol",
draft-ietf-ipp-req-02.txt, June, 1998. draft-ietf-ipp-req-02.txt, June, 1998.
[RFC1123] [RFC1123]
Braden, S., "Requirements for Internet Hosts - Application and Braden, S., "Requirements for Internet Hosts - Application and
Support", RFC 1123, October, 1989. Support", RFC 1123, October, 1989.
[RFC2026]
S. Bradner, "The Internet Standards Process -- Revision 3", RFC
2026, October 1996.
[RFC2068] [RFC2068]
R Fielding, et al, "Hypertext Transfer Protocol . HTTP/1.1" RFC R Fielding, et al, .Hypertext Transfer Protocol . HTTP/1.1. RFC
2068, January 1997. 2068, January 1997.
[rfc2119] [rfc2119]
S. Bradner, "Key words for use in RFCs to Indicate Requirement S. Bradner, "Key words for use in RFCs to Indicate Requirement
Levels", RFC 2119 , March 1997. Levels", RFC 2119 , March 1997.
[RFC2396] [RFC2396]
Berners-Lee, T., Fielding, R., Masinter, L., "Uniform Resource Berners-Lee, T., Fielding, R., Masinter, L., "Uniform Resource
Identifiers (URI): Generic Syntax", RFC 2396, August 1998. Identifiers (URI): Generic Syntax", RFC 2396, August 1998.
[Servlet]
Servlet Specification Version 2.1
(http://java.sun.com/products/servlet/2.1/index.html).
[SSL] [SSL]
Netscape, The SSL Protocol, Version 3, (Text version 3.02), Netscape, The SSL Protocol, Version 3, (Text version 3.02),
November 1996. November 1996.
4.1 Authors' Address 4.1 Authors. Address
Thomas N. Hastings Thomas N. Hastings
Xerox Corporation Xerox Corporation
701 Aviation Blvd. 701 Aviation Blvd.
Expires May 16, 1999
El Segundo, CA 90245 El Segundo, CA 90245
hastings@cp10.es.xerox.com hastings@cp10.es.xerox.com
Carl-Uno Manros Carl-Uno Manros
Expires August 12, 1999
Xerox Corporation Xerox Corporation
701 Aviation Blvd. 701 Aviation Blvd.
El Segundo, CA 90245 El Segundo, CA 90245
manros@cp10.es.xerox.com manros@cp10.es.xerox.com
5 Appendix C: Full Copyright Statement 5 Notices
Copyright (C) The Internet Society (1998). All Rights Reserved The IETF takes no position regarding the validity or scope of any
intellectual property or other rights that might be claimed to pertain
to the implementation or use of the technology described in this
document or the extent to which any license under such rights might or
might not be available; neither does it represent that it has made any
effort to identify any such rights. Information on the IETF's
procedures with respect to rights in standards-track and standards-
related documentation can be found in BCP-11[BCP-11]. Copies of claims
of rights made available for publication and any assurances of licenses
to be made available, or the result of an attempt made to obtain a
general license or permission for the use of such proprietary rights by
implementers or users of this specification can be obtained from the
IETF Secretariat.
The IETF invites any interested party to bring to its attention any
copyrights, patents or patent applications, or other proprietary rights
which may cover technology that may be required to practice this
standard. Please address the information to the IETF Executive
Director.
Copyright (C) The Internet Society (1999). All Rights Reserved.
This document and translations of it may be copied and furnished to This document and translations of it may be copied and furnished to
others, and derivative works that comment on or otherwise explain it or others, and derivative works that comment on or otherwise explain it or
assist in its implementation may be prepared, copied, published and assist in its implementation may be prepared, copied, published and
distributed, in whole or in part, without restriction of any kind, distributed, in whole or in part, without restriction of any kind,
provided that the above copyright notice and this paragraph are included provided that the above copyright notice and this paragraph are included
on all such copies and derivative works. However, this document itself on all such copies and derivative works. However, this document itself
may not be modified in any way, such as by removing the copyright notice may not be modified in any way, such as by removing the copyright notice
or references to the Internet Society or other Internet organizations, or references to the Internet Society or other Internet organizations,
except as needed for the purpose of developing Internet standards in except as needed for the purpose of developing Internet standards in
skipping to change at line 2379 skipping to change at page 57, line 5
The limited permissions granted above are perpetual and will not be The limited permissions granted above are perpetual and will not be
revoked by the Internet Society or its successors or assigns. revoked by the Internet Society or its successors or assigns.
This document and the information contained herein is provided on an "AS This document and the information contained herein is provided on an "AS
IS" basis and THE INTERNET SOCIETY AND THE INTERNET ENGINEERING TASK IS" basis and THE INTERNET SOCIETY AND THE INTERNET ENGINEERING TASK
FORCE DISCLAIMS ALL WARRANTIES, EXPRESS OR IMPLIED, INCLUDING BUT NOT FORCE DISCLAIMS ALL WARRANTIES, EXPRESS OR IMPLIED, INCLUDING BUT NOT
LIMITED TO ANY WARRANTY THAT THE USE OF THE INFORMATION HEREIN WILL NOT LIMITED TO ANY WARRANTY THAT THE USE OF THE INFORMATION HEREIN WILL NOT
INFRINGE ANY RIGHTS OR ANY IMPLIED WARRANTIES OF MERCHANTABILITY OR INFRINGE ANY RIGHTS OR ANY IMPLIED WARRANTIES OF MERCHANTABILITY OR
FITNESS FOR A PARTICULAR PURPOSE. FITNESS FOR A PARTICULAR PURPOSE.
Expires May 16, 1999 Expires August 12, 1999
6 Change History
The change history is in reverse chronological order:
6.1 Changes to produce the February 12, 1999 version from the January 8,
1999 version:
1. Section 2.2.1.5: added check for document not found or accessible
in Print-URI and Send-URI
2. Section 3.6.2: Clarified that the IPP standard requires that
servers MUST accept chunked requests and that clients MUST accept
chunked responses, in spite of the lack of conformance of HTTP
servers to the HTTP/1.1 requirement to support chunking.
6.2 Changes to produce the January 8, 1999 version from the December 6,
1998 version:
1. Added section 3.6.2: Warning About the Use of Chunked Requests
with CGI Script Implementations
2. Section 2.2.1.2: changed "printer-operations-supported" to
"operations-supported".
3. Section 2.2.1.6: changed "job-media-supported" to "job-media-
sheets-supported"
4. Section 2.2.3: separated the validation checks for variable length
attributes into two separate tests: one for correct attribute
syntax and one for correct length.
5. Section 2.2.3: changed "multiple-document-handling-supported" to
"printer-resolution-supported"
6. Section 2.6.1: recommended that an IPP object also support US-
ASCII charset.
7. Section 3: Clarified that a server is not required to send a
response until after it has received the client.s entire request,
but recommend that the server return a response as soon as possible
if an error is detected while the client is still sending the data,
rather than waiting until all of the data is received. Also
recommended that a client listen for an error response that an IPP
server MAY send before it receives all the data.
6.3 Changes to produce the December 6, 1998 version from the November
16, 1998 version:
Included all of the remaining agreed issues raised before the November
16, 1998 production of the Internet-Drafts for IPP/1.0 that included
adding explanations to the Implementers Guide.
Expires August 12, 1999
Expires August 12, 1999
 End of changes. 246 change blocks. 
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