Internet Draft A. Melnikov
Document: draft-melnikov-imap-ext-abnf Isode Ltd.
Expires: July 2006 Cyrus Daboo
Updates: RFC 3501, RFC 2342, RFC 2088, RFC 3502 and RFC 3516
January 2006
Collected extensions to IMAP4 ABNF
draft-melnikov-imap-ext-abnf-07
draft-melnikov-imap-ext-abnf-08
Status of this Memo
By submitting this Internet-Draft, each author represents that any
applicable patent or other IPR claims of which he or she is aware
have been or will be disclosed, and any of which he or she becomes
aware will be disclosed, in accordance with Section 6 of BCP 79.
Internet-Drafts are working documents of the Internet Engineering
Task Force (IETF), its areas, and its working groups. Note that
other groups may also distribute working documents as Internet-
Drafts.
Internet-Drafts are draft documents valid for a maximum of six
months and may be updated, replaced, or obsoleted by other
documents at any time. It is inappropriate to use Internet-Drafts
as reference material or to cite them other than as "work in
progress."
The list of current Internet-Drafts can be accessed at
http://www.ietf.org/ietf/1id-abstracts.txt
The list of Internet-Draft Shadow Directories can be accessed at
http://www.ietf.org/shadow.html.
A revised version of this draft document will be submitted to the
RFC editor as a Standard Track RFC for the Internet Community.
Discussion and suggestions for improvement are requested, and
should be sent to ietf-imapext@imc.org and/or lemonade@ietf.org.
Distribution of this memo is unlimited.
Abstract
Over years many documents from IMAPEXT and LEMONADE working groups,
as well as many individual documents have added syntactic
extensions to many base IMAP commands described in RFC 3501. For
ease of reference this document collects most of such ABNF changes
in one place.
This document also suggest a set of standard patterns for adding
options and extensions to several existing IMAP commands defined in
RFC 3501. The patterns provide for compatibility between existing
and future extensions.
This document updates ABNF in RFC 3501, RFC 2342, RFC 2088, RFC
3502 and RFC 3516. It also includes part of the errata to RFC 3501.
This document doesn't specify any semantic changes to the listed
RFCs.
Table of Contents
1. Introduction and Conventions Used 3
1.1 Purpose of this document 3
1.2 Conventions Used in this document 4
2. IMAP ABNF extensions 4
2.1 Optional parameters with the SELECT/EXAMINE commands 4
2.2 Extended CREATE command 5
2.3 Extended RENAME command 6
2.4 Extensions to FETCH and UID FETCH Commands 6
2.5 Extensions to STORE and UID STORE Commands 7
2.6 Extensions to SEARCH Command 8
2.7 Extensions to APPEND Command 9
3. Formal Syntax 9
4. Security Considerations 14
5. IANA Considerations 15
6. References 15
6.1 Normative References 15
7. Acknowledgments 16
8. Authors' Addresses 16
9. Full Copyright Statement 16
10. Intellectual Property 17
11. Appendix A. Editorial. 17
11.1 Change Log 18
1. Introduction and Conventions Used
1.1 Purpose of this document
This document serves several purposes:
1. rationalize and generalize ABNF for some existing IMAP
extensions;
2. collect the ABNF in one place in order to minimize cross
references between documents;
3. define building blocks for future extensions so that they can
be used together in a compatible way.
It is expected that a future revision of this document gets
incorporated into a revision of RFC 3501.
This document updates ABNF in RFC 2342, 3501, RFC 2088, RFC 3502
and RFC 3516. It also includes part of the errata to RFC 3501. This
document doesn't specify any semantic changes to the listed RFCs.
The ABNF in section 6 of RFC 2342 got rewritten to conform to the
ABNF syntax as defined in RFC 4234 and to reference new non-
terminals from RFC 3501. It was also restructured to allow for
better readability. There were no changes "on the wire".
Section 2 extends ABNF for SELECT, EXAMINE, CREATE, RENAME, FETCH
/UID FETCH, STORE/UID STORE, SEARCH and APPEND commands in a
consistent manner. Extensions to all the commands but APPEND have
the same structure. Extensibility for the APPEND command was done
slightly differently in order to preserve backward compatibility
with existing extensions.
Section 2 also defines a new ESEARCH response which purpose is to
define a better version of the SEARCH response defined in RFC 3501.
Section 3 defines the collected ABNF that replaces pieces of ABNF
in the aforementioned RFCs. The collected ABNF got generalized to
allow for easier future extensibility.
1.2 Conventions Used in this document
In examples, "C:" and "S:" indicate lines sent by the client and
server respectively.
The key words "MUST", "MUST NOT", "SHOULD", "SHOULD NOT", and "MAY"
in this document are to be interpreted as defined in "Key words for
use in RFCs to Indicate Requirement Levels" [KEYWORDS].
<<Editorial comments and questions are enclosed like this>>
2. IMAP ABNF extensions
This section is not normative. It provides some background on the
intended use of different extensions and it gives some guidance
about how future extensions should extend the described commands.
2.1 Optional parameters with the SELECT/EXAMINE commands
This documents adds the ability to include one or more parameters
with the IMAP SELECT (section 6.3.1 of [IMAP4]) or EXAMINE (section
6.3.2 of [IMAP4]) commands, to turn on or off certain standard
behaviours, or to add new optional behaviours required for a
particular extension.
There are two possible modes of operation:
o A global state change where a single use of the optional
parameter will affect the session state from that time on,
irrespective of subsequent SELECT/EXAMINE commands.
o A per-mailbox state change that will affect the session only for
the duration of the new selected state. A subsequent SELECT/
EXAMINE without the optional parameter will cancel its effect
for the newly selected mailbox.
Optional parameters to the SELECT or EXAMINE commands are added as
a parenthesised list of attribute/value pairs, and appear after the
mailbox name in the standard SELECT or EXAMINE command. The order
of individual parameters is arbitrary. A parameter value is
optional and may consist of atoms, strings or lists in a specific
order. If the parameter value is present, it always appears in
parentheses (*). Any parameter not defined by extensions that the
server supports must be rejected with a BAD response.
Example:
C: a SELECT INBOX (ANNOTATE)
S: ...
S: a OK SELECT complete
In the above example, a single parameter is used with the SELECT
command.
Example:
C: a EXAMINE INBOX (ANNOTATE RESPONSES ("UID Responses")
CONDSTORE)
S: ...
S: a OK EXAMINE complete
In the above example, three parameters are used with the EXAMINE
command. The second parameter consists of two items: an atom
"RESPONSES" followed by a quoted string.
Example:
C: a SELECT INBOX (BLURDYBLOOP)
S: a BAD Unknown parameter in SELECT command
In the above example, a parameter not supported by the server is
used. This results in the BAD response from the
server.
(*) - if a parameter has a mandatory value, which can always be
represented as a number or a sequence-set, the parameter value does
not need the enclosing (). See ABNF for more details.
2.2 Extended CREATE command
Arguments: mailbox name
OPTIONAL list of CREATE parameters
Responses: no specific responses for this command
Result: OK - create completed
NO - create failure: can not create mailbox with
that name
BAD - argument(s) invalid
This documents adds the ability to include one or more parameters
with the IMAP CREATE command (see section 6.3.3 of [IMAP4]), to
turn on or off certain standard behaviour, or to add new optional
behaviours required for a particular extension. No CREATE
parameters are defined in this document.
Optional parameters to the CREATE command are added as a
parenthesised list of attribute/value pairs after the mailbox name.
The order of individual parameters is arbitrary. A parameter value
is optional and may consist of atoms, strings or lists in a
specific order. If the parameter value is present, it always
appears in parentheses (*). Any parameter not defined by extensions
that the server supports must be rejected with a BAD response.
(*) - if a parameter has a mandatory value, which can always be
represented as a number or a sequence-set, the parameter value does
not need the enclosing (). See ABNF for more details.
2.3 Extended RENAME command
Arguments: existing mailbox name
new mailbox name
OPTIONAL list of RENAME parameters
Responses: no specific responses for this command
Result: OK - rename completed
NO - rename failure: can not rename mailbox with
that name, can not rename to mailbox with
that name, etc.
BAD - argument(s) invalid
This documents adds the ability to include one or more parameters
with the IMAP RENAME command (see section 6.3.5 of [IMAP4]), to
turn on or off certain standard behaviour, or to add new optional
behaviours required for a particular extension. No RENAME
parameters are defined in this document.
Optional parameters to the RENAME command are added as a
parenthesised list of attribute/value pairs after the new mailbox
name. The order of individual parameters is arbitrary. A parameter
value is optional and may consist of atoms, strings or lists in a
specific order. If the parameter value is present, it always
appears in parentheses (*). Any parameter not defined by extensions
that the server supports must be rejected with a BAD response.
(*) - if a parameter has a mandatory value, which can always be
represented as a number or a sequence-set, the parameter value does
not need the enclosing (). See ABNF for more details.
2.4 Extensions to FETCH and UID FETCH Commands
Arguments: sequence set
message data item names or macro
OPTIONAL fetch modifiers
Responses: untagged responses: FETCH
Result: OK - fetch completed
NO - fetch error: can not fetch that data
BAD - command unknown or arguments invalid
This document extends the syntax of the FETCH and UID FETCH
commands (see section 6.4.5 of [IMAP4]) to include optional FETCH
modifiers. No fetch modifiers are defined in this document.
The order of individual modifiers is arbitrary. Each modified is
an attribute/value pair. A modifier value is optional and may
consist of atoms and/or strings and/or lists in a specific order.
If the modifier value is present, it always appears in parentheses
(*). Any modifiers not defined by extensions that the server
supports must be rejected with a BAD response.
(*) - if a modifier has a mandatory value, which can always be
represented as a number or a sequence-set, the modifier value does
not need the enclosing (). See ABNF for more details.
2.5 Extensions to STORE and UID STORE Commands
Arguments: message set
OPTIONAL store modifiers
message data item name
value for message data item
Responses: untagged responses: FETCH
Result: OK - store completed
NO - store error: can not store that data
BAD - command unknown or arguments invalid
This document extends the syntax of the STORE and UID STORE
commands (see section 6.4.6 of [IMAP4]) to include optional STORE
modifiers. No store modifiers are defined in this document.
The order of individual modifiers is arbitrary. Each modified is
an attribute/value pair. A modifier value is optional and may
consist of atoms and/or strings and/or lists in a specific order.
If the modifier value is present, it always appears in parentheses
(*). Any modifiers not defined by extensions that the server
supports must be rejected with a BAD response.
(*) - if a modifier has a mandatory value, which can always be
represented as a number or a sequence-set, the modifier value does
not need the enclosing (). See ABNF for more details.
2.6 Extensions to SEARCH Command
2.6.1 Extended SEARCH command
Arguments: OPTIONAL result specifier
OPTIONAL [CHARSET] specification
searching criteria (one or more)
Responses: REQUIRED untagged response: SEARCH (*)
Result: OK - search completed
NO - search error: can not search that [CHARSET] or
criteria
BAD - command unknown or arguments invalid
This section updates definition of the SEARCH command described in
section 6.4.4 of [IMAP4].
The SEARCH command is extended to allow for result options. This
document does not define any result options.
The order of individual options is arbitrary. Individual options
may contain parameters enclosed in parentheses (**). If an option
has parameters, they consist of atoms and/or strings and/or lists
in a specific order. Any options not defined by extensions that the
server supports must be rejected with a BAD response.
(*) - An extension to the SEARCH command may require another
untagged response, or no untagged response to be returned. Section
2.6.2 defines a new ESEARCH untagged response, that replaces the
SEARCH untagged response. Note that for a given extended SEARCH
command the SEARCH and ESEARCH responses SHOULD be mutually
exclusive, i.e. only one of them should be returned.
(**) - if an option has a mandatory parameter, which can always be
represented as a number or a sequence-set, the option parameter
does not need the enclosing (). See ABNF for more details.
2.6.2 ESEARCH untagged response
Contents: one or more search-return-data pairs
The ESEARCH response SHOULD be sent as a result of an extended
SEARCH or UID SEARCH command specified in section 2.6.1.
The ESEARCH response starts with an optional search correlator. If
it is missing then the response was not caused by a particular IMAP
command, whereas if it is present it contains the tag of the
command that caused the response to be returned.
The search correlator is followed by an optional UID indicator. If
this indicator is present, all data in the ESEARCH response refers
to UIDs, otherwise all returned data refers to message numbers.
The rest of the ESEARCH response contains one or more search data
pairs. Each pair starts with unique return item name, followed by a
space and the corresponding data. Search data pairs may be returned
in any order. Unless specified otherwise by an extension, any
return item name SHOULD appear only once in an ESEARCH response.
Example: S: * ESEARCH UID COUNT 5 ALL 4:19,21,28
Example: S: * ESEARCH (TAG "a567") UID COUNT 5 ALL 4:19,21,28
Example: S: * ESEARCH COUNT 5 ALL 1:17,21
2.7 Extensions to APPEND Command
The IMAP BINARY extension [BINARY] extends the APPEND command to
allow a client to append data
containing NULs by using the <literal8> syntax. The ABNF was
rewritten to allow for easier extensibility by IMAP extensions.
This document hasn't specified any semantical changes to the
[BINARY] extension.
In addition, the non-terminal "literal8" defined in [BINARY] got
extended to allow for non-syncronizing literals if both [BINARY]
and [LITERAL+] extensions are supported by the server.
The IMAP MULTIAPPEND extension [MULTIAPPEND] extends the APPEND
command to allow a client to append multiple messages atomically.
This document defines a common syntax for the APPEND command that
takes into considerations syntactic extensions defined by both
[BINARY] and [MULTIAPPEND] extensions.
3. Formal Syntax
The following syntax specification uses the Augmented Backus-Naur
Form (ABNF) notation as specified in [ABNF].
Non-terminals referenced but not defined below are as defined by
[IMAP4].
Except as noted otherwise, all alphabetic characters are case-
insensitive. The use of upper or lower case characters to define
token strings is for editorial clarity only. Implementations MUST
accept these strings in a case-insensitive fashion.
append = "APPEND" SP mailbox 1*append-message
;; only a single append-message may appear
;; if MULTIAPPEND [MULTIAPPEND] capability
;; is not present
append-message = append-opts SP append-data
append-ext = append-ext-name SP append-ext-value
;; This non-terminal define extensions to
;; to message metadata.
append-ext-name = tagged-ext-label
append-ext-value= tagged-ext-val
;; This non-terminal shows recommended syntax
;; for future extensions.
append-data = literal / literal8 / append-data-ext
append-data-ext = tagged-ext
;; This non-terminal shows recommended syntax
;; for future extensions,
;; i.e. a mandatory label followed
;; by parameters.
append-opts = [SP flag-list] [SP date-time] *(SP append-ext)
;; message metadata
charset = atom / quoted
;; Exact syntax is defined in [CHARSET].
create = "CREATE" SP mailbox
[create-params]
;; Use of INBOX gives a NO error.
create-params = SP "(" create-param *( SP create-param) ")"
create-param-name = tagged-ext-label
create-param = create-param-name [SP create-param-value]
create-param-value= tagged-ext-val
;; This non-terminal shows recommended syntax
;; for future extensions.
esearch-response = "ESEARCH" [search-correlator] [SP "UID"]
*(SP search-return-data)
;; Note that SEARCH and ESEARCH responses
;; SHOULD be mutually exclusive,
;; i.e. only one of the response types
;; should be
;; returned as a result of a command.
examine = "EXAMINE" SP mailbox [select-params]
;; modifies the original IMAP EXAMINE command
;; to accept optional parameters
fetch = "FETCH" SP sequence-set SP ("ALL" / "FULL" /
"FAST" / fetch-att /
"(" fetch-att *(SP fetch-att) ")")
[fetch-modifiers]
;; modifies the original IMAP4 FETCH command to
;; accept optional modifiers
fetch-modifiers = SP "(" fetch-modifier *(SP fetch-modifier) ")"
fetch-modifier = fetch-modifier-name [ SP fetch-modif-params ]
fetch-modif-params = tagged-ext-val
;; This non-terminal shows recommended syntax
;; for future extensions.
fetch-modifier-name = tagged-ext-label
literal8 = "~{" number ["+"] "}" CRLF *OCTET
;; A string that might contain NULs.
;; <number> represents the number of OCTETs
;; in the response string.
;; The "+" is only allowed when both LITERAL+
;; and BINARY extensions are supported
;; by the server.
mailbox-data =/ Namespace-Response /
esearch-response
Namespace = nil / "(" 1*Namespace-Descr ")"
Namespace-Command = "NAMESPACE"
Namespace-Descr = "(" string SP
(DQUOTE QUOTED-CHAR DQUOTE / nil)
*(Namespace-Response-Extension) ")"
Namespace-Response-Extension = SP string SP
"(" string *(SP string) ")"
Namespace-Response = "NAMESPACE" SP Namespace
SP Namespace SP Namespace
;; This response is currently only allowed
;; if the IMAP server supports [RFC 2342].
;; The first Namespace is the Personal Namespace(s)
;; The second Namespace is the Other Users' Namespace(s)
;; The third Namespace is the Shared Namespace(s)
rename = "RENAME" SP mailbox SP mailbox
[rename-params]
;; Use of INBOX as a destination gives
;; a NO error, unless rename-params
;; is not empty.
rename-params = SP "(" rename-param *( SP rename-param) ")"
rename-param = rename-param-name [SP rename-param-value]
rename-param-name = tagged-ext-label
rename-param-value= tagged-ext-val
;; This non-terminal shows recommended syntax
;; for future extensions.
response-data = "*" SP response-payload CRLF
response-payload= resp-cond-state / resp-cond-bye /
mailbox-data / message-data / capability-data
search = "SEARCH" [search-return-opts]
search-program
search-correlator = SP "(" "TAG" SP tag-string ")"
search-program = [SP "CHARSET" SP charset] 1*(SP search-key)
;; CHARSET argument to SEARCH MUST be
;; registered with IANA.
search-return-data = search-modifier-name SP search-return-value
;; Note that not every SEARCH return option
;; is required to have the corresponding
;; ESEARCH return data.
search-return-opts = SP "RETURN" SP "(" [search-return-opt
*(SP search-return-opt)] ")"
search-return-opt = search-modifier-name [SP search-mod-params]
search-return-value = tagged-ext-val
;; Data for the returned search option.
;; A single "nz-number"/"number" value
;; can be returned as an atom (i.e. without
;; quoting). A sequence-set can be returned
;; as an atom as well.
search-modifier-name = tagged-ext-label
search-mod-params = tagged-ext-val
;; This non-terminal shows recommended syntax
;; for future extensions.
select = "SELECT" SP mailbox [select-params]
;; modifies the original IMAP SELECT command to
;; accept optional parameters
select-params = SP "(" select-param *(SP select-param) ")"
select-param = select-param-name [SP select-param-value]
;; a parameter to SELECT may contain one or
;; more atoms and/or strings and/or lists.
select-param-name= tagged-ext-label
select-param-value= tagged-ext-val
;; This non-terminal shows recommended syntax
;; for future extensions.
status-att-list = status-att-val *(SP status-att-val)
;; Redefines status-att-list from RFC 3501.
;; status-att-val is defined in RFC 3501 errata
status-att-val = ("MESSAGES" SP number) /
("RECENT" SP number) /
("UIDNEXT" SP nz-number) /
("UIDVALIDITY" SP nz-number) /
("UNSEEN" SP number)
;; Extensions to the STATUS responses
;; should extend this production.
;; Extensions should use the generic
;; syntax defined by tagged-ext.
store = "STORE" SP sequence-set [store-modifiers]
SP store-att-flags
;; extend [IMAP4] STORE command syntax
;; to allow for optional store-modifiers
store-modifiers = SP "(" store-modifier *(SP store-modifier)
")"
store-modifier = store-modifier-name [SP store-modif-params]
store-modif-params = tagged-ext-val
;; This non-terminal shows recommended syntax
;; for future extensions.
store-modifier-name = tagged-ext-label
tag-string = string
;; tag of the command that caused
;; the ESEARCH response, sent as
;; a string.
tagged-ext = tagged-ext-label SP tagged-ext-val
;; recommended overarching syntax for
;; extensions
tagged-ext-label = tagged-label-fchar *tagged-label-char
;; Is a valid RFC 3501 "atom".
tagged-label-fchar = ALPHA / "-" / "_" / "."
tagged-label-char = tagged-label-fchar / DIGIT / ":"
tagged-ext-comp = astring /
tagged-ext-comp *(SP tagged-ext-comp) /
"(" tagged-ext-comp ")"
;; Extensions that follow this general
;; syntax should use nstring instead of
;; astring when appropriate in the context
;; of the extension.
;; Note that a message set or a "number"
;; can always be represented as an "atom".
;; An URL should be represented as
;; a "quoted" string.
tagged-ext-simple = sequence-set / number
tagged-ext-val = tagged-ext-simple /
"(" [tagged-ext-comp] ")"
4. Security Considerations
This document updates ABNF in RFC 3501, RFC 2342, RFC 2088, RFC
3502 and RFC 3516. The updated documents must be consulted for
security considerations for the extensions that they define.
As a protocol gets more complex, parser bugs become more common
including buffer overflow, denial of service and other common
security coding errors. To the extent this document makes the
parser more complex, it makes this situation worse. To this extent
this document makes the parser more consistent and thus simpler,
the situation is improved. The impact will depend on how many
deployed IMAP extensions are consistent with this document.
Implementers are encouraged to take care of these issues when
extending existing implementations. Future IMAP extensions should
strive for consistency and simplicity to the greatest extent
possible.
Extensions to IMAP commands that are permitted in NOT AUTHENTICATED
state are more sensitive to these security issues due to the larger
possible attacker community prior to authentication, and the fact
that some IMAP servers run with elevated privileges in that state.
This document does not extend any commands permitted in NOT
AUTHENTICATED state. Future IMAP extensions to commands permitted
in NOT AUTHENTICATED state should favor simplicity over consistency
or extensibility.
5. IANA Considerations
This document doesn't define any new IMAP extension, so no action
from IANA is required.
6. References
6.1 Normative References
[KEYWORDS] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", RFC 2119, March 1997.
[IMAP4] Crispin, M., "Internet Message Access Protocol - Version
4rev1", RFC 3501, University of Washington, March 2003.
[ABNF] Crocker, D. (Ed.) and P. Overell , "Augmented BNF for Syntax
Specifications: ABNF", RFC 4234, October 2005.
[CHARSET] Freed, N. and J. Postel, "IANA Character Set Registration
Procedures", RFC 2978, October 2000.
[MULTIAPPEND] Crispin, M., "Internet Message Access Protocol
(IMAP) - MULTIAPPEND Extension", RFC 3502, March 2003.
[NAMESPACE] Gahrns, M. and C. Newman, "IMAP4 Namespace", RFC 2342,
May 1998.
[LITERAL+] Myers, J., "IMAP4 non-synchronizing literals", RFC 2088,
January 1997.
[BINARY] Nerenberg, L., "IMAP4 Binary Content Extension", RFC 3516,
April 2003
7. Acknowledgments
This documents is based on ideas proposed by Pete Resnick, Mark
Crispin, Ken Murchison, Philip Guenther, Randall Gellens and Lyndon
Nerenberg.
However all errors and omissions must be attributed to the authors
of the document.
Thanks to Philip Guenther, Dave Cridland, Mark Crispin, Chris
Newman, Elwyn Davies and Barry Leiba for comments and corrections.
literal8 syntax was taken from RFC 3516.
8. Authors' Addresses
Alexey Melnikov
Isode Limited
5 Castle Business Village
36 Station Road
Hampton, Middlesex, TW12 2BX
UK
Email: Alexey.Melnikov@isode.com
Cyrus Daboo
EMail: cyrus@daboo.name
9. Full Copyright Statement
Copyright (C) The Internet Society (2006).
This document is subject to the rights, licenses and restrictions
contained in BCP 78, and except as set forth therein, the authors
retain all their rights.
This document and the information contained herein are provided on
an "AS IS" basis and THE CONTRIBUTOR, THE ORGANIZATION HE/SHE
REPRESENTS OR IS SPONSORED BY (IF ANY), THE INTERNET SOCIETY AND
THE INTERNET ENGINEERING TASK FORCE DISCLAIM ALL WARRANTIES,
EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO ANY WARRANTY THAT
THE USE OF THE INFORMATION HEREIN WILL NOT INFRINGE ANY RIGHTS OR
ANY IMPLIED WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A
PARTICULAR PURPOSE.
10. Intellectual Property
The IETF takes no position regarding the validity or scope of any
Intellectual Property Rights 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; nor does it represent that
it has made any independent effort to identify any such rights.
Information on the procedures with respect to rights in RFC
documents can be found in BCP 78 and BCP 79.
Copies of IPR disclosures made to the IETF Secretariat 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 on-line IPR repository
at http://www.ietf.org/ipr.
The IETF invites any interested party to bring to its attention any
copyrights, patents or patent applications, or other proprietary
rights that may cover technology that may be required to implement
this standard. Please address the information to the IETF at ietf-
ipr@ietf.org.
Acknowledgement
Funding for the RFC Editor function is currently provided by the
Internet Society.
11. Appendix A. Editorial.
11.1 Change Log
00 Initial Revision.
01 Added Cyrus as co-author. Added BINARY literals. Added section
about APPEND. Clarified that the order of all
parameters/modifiers is arbitrary. Unrecognized SELECT/EXAMINE
parameter should cause the BAD, not the NO response.
02 Updated boilerplate. Extended SEARCH modifiers to be consistent
with STORE modifiers. Rewrote FETCH modifier syntax for
consistency.
03 Updated as per comments from Philip (ABNF suggestions, in
particular addition of response-data; normative language).
Incorporated RFC 3501 ABNF errata from Mark. Added extensions to
CREATE and RENAME commands. Updated ABNF to use consistent
grammer for all extension elements (this changed ABNF for
SELECT/EXAMINE and FETCH).
04 Added ESEARCH response. Added search-program from IMAP URL.
Removed the partition parameter from CREATE/RENAME. Added
NAMESPACE command/response.
05 Added non-synchronizing literals (RFC 2088). Clarified generic
syntax for STATUS responses.
06 Updated reference to ABNF. Made CREATE/RENAME/SELECT parameter
values optional (for consistency with other parameters and to
make examples valid), but if a value is present, it must be in
(), unless it is a number or a sequence. Updated description of
CREATE/RENAME/SELECT parameters to match ABNF. Disallow a single
astring parameter with not parentheses. Defined append-ext to be
"atom SP value". Added a missing reference to RFC 3516. Added
missing leading space in the search-return-opts non-terminal.
Rewrote ABNF for STORE and FETCH options for consistency with
others. Added Security Considerations, courtesy of Chris Newman.
Added new non-terminal for charset (from Mark Crispin's RFC 3501
errata). Describe exact syntax for future extensions (as per
IETF LC comment from Mark Crispin).