< draft-leiba-cotton-iana-5226bis-01.txt   draft-leiba-cotton-iana-5226bis-02.txt >
Network Working Group M. Cotton Network Working Group M. Cotton
Internet-Draft Internet Assigned Numbers Internet-Draft ICANN
Obsoletes: 5226 (if approved) Authority (IANA) BCP: 26 B. Leiba
Intended status: BCP B. Leiba Obsoletes: 5226 (if approved) Huawei Technologies
Expires: April 5, 2013 Huawei Technologies Intended status: Best Current Practice T. Narten
T. Narten Expires: September 28, 2013 IBM Corporation
IBM Corporation March 29, 2013
October 2, 2012
Guidelines for Writing an IANA Considerations Section in RFCs Guidelines for Writing an IANA Considerations Section in RFCs
draft-leiba-cotton-iana-5226bis-01 draft-leiba-cotton-iana-5226bis-02
Abstract Abstract
Many protocols make use of identifiers consisting of constants and Many protocols make use of points of extensibility that use constants
other well-known values. Even after a protocol has been defined and to identify various protocol parameters. To ensure that the values
deployment has begun, new values may need to be assigned (such as for used in these fields do not have conflicting uses, and to promote
a new option type in DHCP, or a new encryption or authentication interoperability, their allocation is often coordinated by a central
transform for IPsec). To ensure that such quantities have consistent authority. For IETF protocols, that role is filled by the Internet
values and interpretations across all implementations, their Assigned Numbers Authority (IANA).
assignment must be administered by a central authority. For IETF
protocols, that role is provided by the Internet Assigned Numbers
Authority (IANA).
In order for IANA to manage a given namespace prudently, it needs To manage a given namespace prudently, IANA needs guidance describing
guidelines describing the conditions under which new values can be the conditions under which new values should be assigned, as well as
assigned or when modifications to existing values can be made. If when and how modifications to existing values can be made. This
IANA is expected to play a role in the management of a namespace, document defines a framework for the documentation of these
IANA must be given clear and concise instructions describing that guidelines by specification authors, in order to assure that the
role. This document discusses issues that should be considered in guidance given to IANA is clear and addresses the various issues that
formulating a policy for assigning values to a namespace and provides are likely in the operation of a registry.
guidelines for authors on the specific text that must be included in
documents that place demands on IANA.
This document obsoletes RFC 5226. This is the third edition, and obsoletes RFC 5226.
Status of this Memo Status of this Memo
This Internet-Draft is submitted in full conformance with the This Internet-Draft is submitted in full conformance with the
provisions of BCP 78 and BCP 79. provisions of BCP 78 and BCP 79.
Internet-Drafts are working documents of the Internet Engineering Internet-Drafts are working documents of the Internet Engineering
Task Force (IETF). Note that other groups may also distribute Task Force (IETF). Note that other groups may also distribute
working documents as Internet-Drafts. The list of current Internet- working documents as Internet-Drafts. The list of current Internet-
Drafts is at http://datatracker.ietf.org/drafts/current/. Drafts is at http://datatracker.ietf.org/drafts/current/.
Internet-Drafts are draft documents valid for a maximum of six months Internet-Drafts are draft documents valid for a maximum of six months
and may be updated, replaced, or obsoleted by other documents at any and may be updated, replaced, or obsoleted by other documents at any
time. It is inappropriate to use Internet-Drafts as reference time. It is inappropriate to use Internet-Drafts as reference
material or to cite them other than as "work in progress." material or to cite them other than as "work in progress."
This Internet-Draft will expire on April 5, 2013. This Internet-Draft will expire on September 28, 2013.
Copyright Notice Copyright Notice
Copyright (c) 2012 IETF Trust and the persons identified as the Copyright (c) 2013 IETF Trust and the persons identified as the
document authors. All rights reserved. document authors. All rights reserved.
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Table of Contents Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 5 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 3
1.1. Terminology Used In This Document . . . . . . . . . . . . 5 1.1. Terminology Used In This Document . . . . . . . . . . . . 3
2. Why Management of a Namespace May Be Necessary . . . . . . . . 6 2. Creating and Revising Registries . . . . . . . . . . . . . . . 3
3. Designated Experts . . . . . . . . . . . . . . . . . . . . . . 7 2.1. Documentation Requirements for Registries . . . . . . . . 4
3.1. The Motivation for Designated Experts . . . . . . . . . . 7 2.2. Defining an Appropriate Registry Policy . . . . . . . . . 6
3.2. The Role of the Designated Expert . . . . . . . . . . . . 8 2.2.1. Using the Well-Known Registration Policies . . . . . . 8
3.3. Designated Expert Reviews . . . . . . . . . . . . . . . . 9 2.2.2. Using Multiple Policies in Combination . . . . . . . . 9
3.4. Expert Reviews and the Document Lifecycle . . . . . . . . 10 2.3. Revising Existing Registries . . . . . . . . . . . . . . . 10
4. Creating a Registry . . . . . . . . . . . . . . . . . . . . . 11 3. Registering New Values in an Existing Registry . . . . . . . . 10
4.1. Well-Known IANA Policy Definitions . . . . . . . . . . . . 11 3.1. Documentation Requirements for Registrations . . . . . . . 10
4.1.1. Policy: Private Use . . . . . . . . . . . . . . . . . 12 3.2. Updating Existing Registrations . . . . . . . . . . . . . 12
4.1.2. Policy: Experimental Use . . . . . . . . . . . . . . . 13 3.3. Overriding Registration Procedures . . . . . . . . . . . . 12
4.1.3. Policy: Hierarchical Allocation . . . . . . . . . . . 13 4. Well-Known Registration Policies . . . . . . . . . . . . . . . 13
4.1.4. Policy: First Come First Served . . . . . . . . . . . 13 4.1. Private Use . . . . . . . . . . . . . . . . . . . . . . . 13
4.1.5. Policy: Expert Review . . . . . . . . . . . . . . . . 13 4.2. Experimental Use . . . . . . . . . . . . . . . . . . . . . 14
4.1.6. Policy: Specification Required . . . . . . . . . . . . 14 4.3. Hierarchical Allocation . . . . . . . . . . . . . . . . . 14
4.1.7. Policy: RFC Required . . . . . . . . . . . . . . . . . 14 4.4. First Come First Served . . . . . . . . . . . . . . . . . 14
4.1.8. Policy: IETF Review . . . . . . . . . . . . . . . . . 15 4.5. Expert Review . . . . . . . . . . . . . . . . . . . . . . 15
4.1.9. Policy: Standards Action . . . . . . . . . . . . . . . 15 4.6. Specification Required . . . . . . . . . . . . . . . . . . 15
4.1.10. Policy: IESG Approval . . . . . . . . . . . . . . . . 15 4.7. RFC Required . . . . . . . . . . . . . . . . . . . . . . . 16
4.2. Best Practice for Selecting an Appropriate Policy . . . . 16 4.8. IETF Review . . . . . . . . . . . . . . . . . . . . . . . 16
4.3. Using Multiple Policies in Combination . . . . . . . . . . 19 4.9. Standards Action . . . . . . . . . . . . . . . . . . . . . 16
4.4. What to Put in Documents That Create a Registry . . . . . 19 4.10. IESG Approval . . . . . . . . . . . . . . . . . . . . . . 17
4.5. Updating IANA Guidelines for Existing Registries . . . . . 22 5. Designated Experts . . . . . . . . . . . . . . . . . . . . . . 17
5. Registering New Values in an Existing Registry . . . . . . . . 23 5.1. The Motivation for Designated Experts . . . . . . . . . . 17
5.1. What to Put in Documents When Registering Values . . . . . 23 5.2. The Role of the Designated Expert . . . . . . . . . . . . 18
5.2. Updating Registrations . . . . . . . . . . . . . . . . . . 24 5.3. Designated Expert Reviews . . . . . . . . . . . . . . . . 19
5.3. Overriding Registration Procedures . . . . . . . . . . . . 25 5.4. Expert Reviews and the Document Lifecycle . . . . . . . . 21
6. Documentation References in IANA Registries . . . . . . . . . 26 6. Well-Known Registration Status Terminology . . . . . . . . . . 21
7. What to Do in "bis" Documents . . . . . . . . . . . . . . . . 26 7. Documentation References in IANA Registries . . . . . . . . . 22
8. Miscellaneous Issues . . . . . . . . . . . . . . . . . . . . . 27 8. What to Do in "bis" Documents . . . . . . . . . . . . . . . . 22
8.1. When There Are No IANA Actions . . . . . . . . . . . . . . 27 9. Miscellaneous Issues . . . . . . . . . . . . . . . . . . . . . 23
8.2. Namespaces Lacking Documented Guidance . . . . . . . . . . 28 9.1. When There Are No IANA Actions . . . . . . . . . . . . . . 23
8.3. After-the-Fact Registrations . . . . . . . . . . . . . . . 28 9.2. Namespaces Lacking Documented Guidance . . . . . . . . . . 24
8.4. Reclaiming Assigned Values . . . . . . . . . . . . . . . . 29 9.3. After-the-Fact Registrations . . . . . . . . . . . . . . . 24
8.5. Contact Person vs Assignee or Owner . . . . . . . . . . . 29 9.4. Reclaiming Assigned Values . . . . . . . . . . . . . . . . 25
8.6. Closing or Obsoleting a Registry . . . . . . . . . . . . . 30 9.5. Contact Person vs Assignee or Owner . . . . . . . . . . . 25
8.7. BCP 78/79 Issues in Registries . . . . . . . . . . . . . . 30 9.6. Closing or Obsoleting a Registry . . . . . . . . . . . . . 26
9. Appeals . . . . . . . . . . . . . . . . . . . . . . . . . . . 30 9.7. BCP 78/79 Issues in Registries . . . . . . . . . . . . . . 26
10. Mailing Lists . . . . . . . . . . . . . . . . . . . . . . . . 30 10. Appeals . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
11. Security Considerations . . . . . . . . . . . . . . . . . . . 30 11. Mailing Lists . . . . . . . . . . . . . . . . . . . . . . . . 26
12. Changes Relative to Earlier Editions of BCP 26 . . . . . . . . 31 12. Security Considerations . . . . . . . . . . . . . . . . . . . 26
12.1. 2012: Changes in This Document Relative to RFC 5226 . . . 31 13. To-Do List; resolve and remove before requesting publication . 27
12.2. 2008: Changes in RFC 5226 Relative to RFC 2434 . . . . . . 32 14. Changes Relative to Earlier Editions of BCP 26 . . . . . . . . 27
13. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . 33 14.1. 2013: Changes in This Document Relative to RFC 5226 . . . 27
13.1. Acknowledgments for This Document (2012) . . . . . . . . . 33 14.2. 2008: Changes in RFC 5226 Relative to RFC 2434 . . . . . 28
13.2. Acknowledgments from the second edition (2008) . . . . . . 33 15. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . 28
13.3. Acknowledgments from the first edition (1998) . . . . . . 33 15.1. Acknowledgments for This Document (2013) . . . . . . . . 28
14. References . . . . . . . . . . . . . . . . . . . . . . . . . . 33 15.2. Acknowledgments from the second edition (2008) . . . . . 29
14.1. Normative References . . . . . . . . . . . . . . . . . . . 33 15.3. Acknowledgments from the first edition (1998) . . . . . . 29
14.2. Informative References . . . . . . . . . . . . . . . . . . 33 16. References . . . . . . . . . . . . . . . . . . . . . . . . . . 29
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 36 16.1. Normative References . . . . . . . . . . . . . . . . . . 29
16.2. Informative References . . . . . . . . . . . . . . . . . 29
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 32
1. Introduction 1. Introduction
Many protocols make use of fields that contain constants and other Many protocols make use of points of extensibility that use constants
well-known values (such as the Protocol field in the IP header to identify various protocol parameters. To ensure that the values
[RFC0791] and MIME media types [RFC4288]). Even after a protocol has used in these fields do not have conflicting uses, and to promote
been defined and deployment has begun, new values may need to be interoperability, their allocation is often coordinated by a central
assigned (such as a new option type in DHCP [RFC2132] or a new authority. For IETF protocols, that role is filled by the Internet
encryption or authentication transform for IPsec [RFC4301]). To Assigned Numbers Authority (IANA) [RFC2860].
ensure that such fields have consistent values and interpretations in
different implementations, their assignment must be administered by a
central authority. For IETF protocols, that role is provided by the
Internet Assigned Numbers Authority (IANA) [RFC2860].
In this document, we call the set of possible values for such a field The Protocol field in the IP header [RFC0791] and MIME media types
a "namespace"; its actual value may be a text string, a number, or [RFC4288] are two examples of such coordinations.
another kind of value. The binding or association of a specific
value with a particular purpose within a namespace is called an
assigned number (or assigned value, or sometimes a "code point",
"protocol constant", or "protocol parameter"). Each assignment of a
value in a namespace is called a registration.
In order for IANA to manage a given namespace prudently, it needs In this document, we call the range of possible values for such a
guidelines describing the conditions under which new values should be field a "namespace". The binding or association of a specific value
assigned or when (and how) modifications to existing values can be with a particular purpose within a namespace is called an assignment
made. This document provides guidelines to authors on what sort of (or, variously: an assigned number, assigned value, "code point",
text should be added to their documents in order to provide IANA "protocol constant", or "protocol parameter"). The act of assignment
clear guidelines, and it reviews issues that should be considered in is called a registration, and it takes place in the context of a
formulating an appropriate policy for assigning numbers to name registry.
spaces.
Not all namespaces require centralized administration. In some To manage a given namespace prudently, IANA needs guidance describing
cases, it is possible to delegate a namespace in such a way that the conditions under which new values should be assigned, as well as
further assignments can be made independently and with no further when and how modifications to existing values can be made. This
(central) coordination. In the Domain Name System, for example, IANA document defines a framework for the documentation of these
only deals with assignments at the higher levels, while subdomains guidelines by specification authors, in order to assure that the
are administered by the organization to which the space has been guidance given to IANA is clear and addresses the various issues that
delegated. As another example, Object Identifiers (OIDs) as defined are likely in the operation of a registry.
by the ITU are also delegated [RFC3232]; IANA manages the subtree
rooted at "iso.org.dod.internet" (1.3.6.1) . When a namespace is Typically, this information is recorded in a dedicated section of the
delegated, the scope of IANA is limited to the parts of the namespace specification with the title "IANA Considerations".
where IANA has authority.
1.1. Terminology Used In This Document 1.1. Terminology Used In This Document
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
"SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this
document are to be interpreted as described in RFC 2119 [RFC2119]. document are to be interpreted as described in RFC 2119 [RFC2119].
For this document, "the specification" as used by RFC 2119 refers to For this document, "the specification" as used by RFC 2119 refers to
the processing of protocol documents within the IETF standards the processing of protocol documents within the IETF standards
process. process.
2. Why Management of a Namespace May Be Necessary 2. Creating and Revising Registries
Defining a registry involves describing the namespace(s) to be
created, listing an initial set of assignments (if appropriate), and
documenting guidelines on how future assignments are to be made.
One issue to consider in managing a namespace is its size. If the Before defining a registry, however, consider delegating the
space is small and limited in size, assignments must be made namespace in some manner. This route should be pursued when
carefully to prevent exhaustion of the space. If the space is appropriate, as it lessens the burden on IANA for dealing with
essentially unlimited, on the other hand, potential exhaustion will assignments.
probably not be a practical concern at all. Even when the space is
essentially unlimited, however, it is usually desirable to have at In particular, not all namespaces require a registry; in some cases,
least a minimal review prior to assignment in order to: assignments can be made independently and with no further (central)
coordination. In the Domain Name System, for example, IANA only
deals with assignments at the higher levels, while subdomains are
administered by the organization to which the space has been
delegated. When a namespace is delegated in this manner, the scope
of IANA is limited to the parts of the namespace where IANA has
authority.
2.1. Documentation Requirements for Registries
Documents that create a new namespace (or modify the definition of an
existing space) and that expect IANA to play a role in maintaining
that space (serving as a repository for registered values) MUST
provide clear instructions on details of the namespace, either in the
IANA Considerations section, or referenced from it.
In particular, such instructions MUST include:
The name of the registry (or sub-registry)
This name will appear on the IANA web page and will be referred to
in future documents that need to allocate a value from the new
space. The full name (and abbreviation, if appropriate) should be
provided. It is highly desirable that the chosen name not be
easily confused with the name of another registry.
When creating a sub-registry, the registry that it is a part of
must be identified using its full name, exactly as it appears in
the IANA registry list.
Providing a URL to precisely identify the registry helps IANA
understand the request. Such URLs are usually removed from the
RFC prior to final publication.
For example, a document could contain something like this:
[TO BE REMOVED: This registration should be made in the Foobar
Operational Parameters registry, located at http://www.iana.org
/assignments/foobar-registry]
Required information for registrations
This information may include the need to document relevant
Security Considerations, if any.
Applicable review process
The review process that will apply to all future requests for
registration. See Section 2.2.
Size, format and syntax of registry entries
What fields to record in the registry., and any technical
requirements upon registry entries (e.g., valid ranges for
integers, length limitations on strings, etc.) as well as the
exact format in which registry values should be displayed. For
numeric assignments, one should specify whether values are to be
recorded in decimal, hexadecimal, or some other format. For
strings, the encoding format should be specified (ASCII, UTF8,
etc.).
Initial assignments and reservations
Any initial assignments or registrations to be included. In
addition, any ranges that are to be reserved for "Private Use",
"Reserved", "Unassigned", etc. should be indicated.
For example, a document might specify a new registry by including:
---------------------------------------------------------------
X. IANA Considerations
This document defines a new DHCP option, entitled "FooBar" (see
Section y), assigned a value of TBD1 from the DHCP Option space
[to be removed upon publication:
http://www.iana.org/assignments/bootp-dhcp-parameters]
[RFC2132] [RFC2939]:
Data
Tag Name Length Meaning
---- ---- ------ -------
TBD1 FooBar N FooBar server
The FooBar option also defines an 8-bit FooType field, for which
IANA is to create and maintain a new sub-registry entitled
"FooType values" under the FooBar option. Initial values for the
DHCP FooBar FooType registry are given below; future assignments
are to be made through Expert Review [BCP26].
Assignments consist of a DHCP FooBar FooType name and its
associated value.
Value DHCP FooBar FooType Name Definition
---- ------------------------ ----------
0 Reserved
1 Frobnitz See Section y.1
2 NitzFrob See Section y.2
3-254 Unassigned
255 Reserved
---------------------------------------------------------------
For examples of documents that establish registries, consult
[RFC6195], [RFC3575], [RFC3968], and [RFC4520].
2.2. Defining an Appropriate Registry Policy
There are several issues to consider when defining the policy for the
management of a registry.
If the registry's namespace is limited, assignments will need to be
made carefully to prevent exhaustion.
Even when the space is essentially unlimited, however, it is usually
desirable to have at least a minimal review prior to assignment in
order to:
o prevent the hoarding of or unnecessary wasting of values. For o prevent the hoarding of or unnecessary wasting of values. For
example, if the space consists of text strings, it may be example, if the space consists of text strings, it may be
desirable to prevent entities from obtaining large sets of strings desirable to prevent entities from obtaining large sets of strings
that correspond to desirable names (existing company names, for that correspond to desirable names (existing company names, for
example). example).
o provide a sanity check that the request actually makes sense and o provide a sanity check that the request actually makes sense and
is necessary. Experience has shown that some level of minimal is necessary. Experience has shown that some level of minimal
review from a subject matter expert is useful to prevent review from a subject matter expert is useful to prevent
assignments in cases where the request is malformed or not assignments in cases where the request is malformed or not
actually needed (for example, an existing assignment for an actually needed (for example, an existing assignment for an
essentially equivalent service already exists). essentially equivalent service already exists).
A second consideration is whether it makes sense to delegate the Perhaps most importantly, unreviewed extensions can impact
namespace in some manner. This route should be pursued when interoperability and security. See [RFC6709].
appropriate, as it lessens the burden on IANA for dealing with
assignments.
A third, and perhaps most important, consideration concerns potential
impact on the interoperability of unreviewed extensions. Proposed
protocol extensions generally benefit from community review; indeed,
review is often essential to avoid future interoperability problems
[RFC6709].
When the namespace is essentially unlimited and there are no When the namespace is essentially unlimited and there are no
potential interoperability issues, assigned numbers can safely be potential interoperability or security issues, assigned numbers can
given out to anyone without any subjective review. In such cases, usually be given out to anyone without any subjective review. In
IANA can make assignments directly, provided that IANA is given such cases, IANA can make assignments directly, provided that IANA is
specific instructions on what types of requests it should grant, and given detailed instructions on what types of requests it should
what information must be provided as part of a well-formed request grant, and it is able to do so without exercising subjective
for an assigned number. judgement.
3. Designated Experts When this is not the case, some level of review is required.
However, it's important to balance adequate review and ease of
registration. In many cases, those making registrations will not be
IETF participants; requests often come from other standards
organizations, from organizations not directly involved in standards,
from ad-hoc community work (from an open-source project, for
example), and so on. Registration must not be unnecessarily
difficult, unnecessarily costly (in terms of time and other
resources), nor unnecessarily subject to denial.
3.1. The Motivation for Designated Experts While it is sometimes necessary to restrict what gets registered
(e.g., for limited resources such as bits in a byte, or for items for
which unsupported values can be damaging to protocol operation), in
many cases having what's in use represented in the registry is more
important. Overly strict review criteria and excessive cost (in time
and effort) discourage people from even attempting to make a
registration. If a registry fails to reflect the protocol elements
actually in use, it can adversely affect deployment of protocols on
the Internet, and the registry itself is devalued.
It should be noted that IANA does not create or define assignment In particular, when a registry policy that requires involvement of
policy itself; rather, it carries out policies that have been defined Working Groups, directorates, or other bodies to be actively involved
by others and published in RFCs. IANA must be given a set of and to support the effort, requests frequently run into concerns that
guidelines that allow it to make allocation decisions with minimal "it's not worth doing a Standards-Track RFC for something this
subjectivity and without requiring any technical expertise with trivial," when, in fact, that requirement was created by the Working
respect to the protocols that make use of a registry. Group in the first place, by placing the bar that high.
In many cases, some review of prospective allocations is appropriate, Indeed, publishing any RFC is costly, and a Standards Track RFC is
and the question becomes who should perform the review and what is especially so, requiring a great deal of community time for review
the purpose of the review. One might think that an IETF working and discussion, IETF-wide last call, involvement of the entire IESG
group familiar with the namespace at hand should be consulted. In as well as concentrated time and review from the sponsoring AD,
practice, however, working groups eventually disband, so they cannot review and action by IANA, and RFC-Editor processing.
be considered a permanent evaluator. It is also possible for
namespaces to be created through individual submission documents, for
which no working group is ever formed.
One way to ensure community review of prospective assignments is to Therefore, Working Groups and other document developers should use
have the requester submit a document for publication as an RFC. Such care in selecting appropriate registration policies when their
an action helps ensure that the specification is publicly and documents create registries. They should select the least strict
permanently available, and it allows some review of the specification policy that suits a registry's needs, and look for specific
prior to publication and assignment of the requested code points. justification for policies that require significant community
This is the preferred way of ensuring review, and is particularly involvement (Specification Required, in terms of the well-known
important if any potential interoperability issues can arise. For policies).
example, some assignments are not just assignments, but also involve
an element of protocol specification. A new option may define fields
that need to be parsed and acted on, which (if specified poorly) may
not fit cleanly with the architecture of other options or the base
protocols on which they are built.
In some cases, however, the burden of publishing an RFC in order to 2.2.1. Using the Well-Known Registration Policies
get an assignment is excessive. However, it is generally still
useful (and sometimes necessary) to discuss proposed additions on a
mailing list dedicated to the purpose (such as the
media-types@iana.org for media types) or on a more general mailing
list (such as that of a current or former IETF working group). Such
a mailing list provides a way for new registrations to be publicly
reviewed prior to getting assigned, or gives advice to persons
wanting help in understanding what a proper registration should
contain.
While discussion on a mailing list can provide valuable technical This document defines a number of registration policies in Section 4.
feedback, opinions may vary and discussions may continue for some Because they benefit from both community experience and wide
time without clear resolution. In addition, IANA cannot participate understanding, their use is encouraged when appropriate.
in all of these mailing lists and cannot determine if or when such
discussions reach consensus. Therefore, IANA relies on a "designated
expert" for advice regarding the specific question of whether an
assignment should be made. The designated expert is an individual
who is responsible for carrying out an appropriate evaluation and
returning a recommendation to IANA.
It should be noted that a key motivation for having designated It is also acceptable to cite one of the well-known policies and
experts is for the IETF to provide IANA with a subject matter expert include additional guidelines for what kind of considerations should
to whom the evaluation process can be delegated. IANA forwards be taken into account by the review process.
requests for an assignment to the expert for evaluation, and the
expert (after performing the evaluation) informs IANA as to whether
or not to make the assignment or registration.
It will often be useful to use a designated expert only some of the For example, RADIUS [RFC3575] specifies the use of a Designated
time, as a supplement to other processes. For more discussion of Expert, but includes specific additional criteria the Designated
that topic, see Section 4.3. Expert should follow.
3.2. The Role of the Designated Expert The well-known policies from "First Come First Served" to "Standards
Action" specify a range of policies in increasing order of
strictness:
The designated expert is responsible for initiating and coordinating 4. First Come First Served
the appropriate review of an assignment request. The review may be No review, minimal documentation.
wide or narrow, depending on the situation and the judgment of the
designated expert. This may involve consultation with a set of
technology experts, discussion on a public mailing list, consultation
with a working group (or its mailing list if the working group has
disbanded), etc. Ideally, the designated expert follows specific
review criteria as documented with the protocol that creates or uses
the namespace. See the IANA Considerations sections of [RFC3748] and
[RFC3575] for examples that have been done for specific namespaces.
Designated experts are expected to be able to defend their decisions 5. Expert Review
to the IETF community, and the evaluation process is not intended to Expert review, sufficient documentation for review.
be secretive or bestow unquestioned power on the expert. Experts are
expected to apply applicable documented review or vetting procedures,
or in the absence of documented criteria, follow generally accepted
norms such as those in Section 3.3.
Section 5.2 discusses disputes and appeals in more detail. 6. Specification Required
Expert review, significant, stable public documentation.
Designated experts are appointed by the IESG (normally upon 7. RFC Required
recommendation by the relevant Area Director). They are typically Any RFC publication, IETF or a non-IETF Stream.
named at the time a document creating or updating a namespace is
approved by the IESG, but as experts originally appointed may later
become unavailable, the IESG will appoint replacements if necessary.
For some registries, it has proven useful to have multiple designated 8. IETF Review
experts. Sometimes those experts work together in evaluating a RFC publication, IETF Stream only, but need not be Standards
request, while in other cases additional experts serve as backups. Track.
In cases of disagreement among those experts, it is the 9. Standards Action
responsibility of those experts to make a single clear recommendation RFC publication, IETF Stream, Standards Track only.
to IANA. It is not appropriate for IANA to resolve disputes among
experts. In extreme situations, such as deadlock, the IESG may need
to step in to resolve the problem.
In registries where a pool of experts evaluates requests, the pool Examples of situations that might merit RFC Required, IETF Review, or
should have a single chair responsible for defining how requests are Standards Action include the following:
to be assigned to and reviewed by experts. In some cases, the expert
pool may consist of a primary and backups, with the backups involved
only when the primary expert is unavailable. In other cases, IANA
might assign requests to individual members in sequential or
approximate random order. In the event that IANA finds itself having
received conflicting advice from its experts, it is the
responsibility of the pool's chair to resolve the issue and provide
IANA with clear instructions.
Since the designated experts are appointed by the IESG, they may be o When a resource is limited, such as bits in a byte (or in two
removed by the IESG. bytes, or four), or numbers in a limited range. In these cases,
allowing registrations that haven't been carefully reviewed and
agreed by community consensus could too quickly deplete the
allowable values.
3.3. Designated Expert Reviews o When thorough community review is necessary to avoid extending or
modifying the protocol in ways that could be damaging. One
example is in defining new command codes, as opposed to options
that use existing command codes: the former might require a strict
policy, where a more relaxed policy could be adequate for the
latter. Another example is in defining protocol elements that
change the semantics of existing operations.
In the years since RFC 2434 was published and has been put to use, The description in Section 4.10 of "IESG Approval" suggests that the
experience has led to the following observations: IESG "can (and should) reject a request if another path for
registration is available that is more appropriate and there is no
compelling reason not to use that path." The IESG should give
similar consideration to any registration policy more stringent than
Specification Required, asking for justification and ensuring that
more relaxed policies have been considered, and the strict policy is
the right one.
o A designated expert must respond in a timely fashion, normally Accordingly, document developers need to anticipate this and document
within a week for simple requests to a few weeks for more complex their considerations for selecting the specified policy (ideally, in
ones. Unreasonable delays can cause significant problems for the document itself; failing that, in the shepherd writeup).
those needing assignments, such as when products need code points Likewise, the document shepherd should ensure that the selected
to ship. This is not to say that all reviews can be completed policies have been justified before sending the document to the IESG.
under a firm deadline, but they must be started, and the requester
and IANA should have some transparency into the process if an
answer cannot be given quickly.
o If a designated expert does not respond to IANA's requests within When specifications are revised, registration policies should be
a reasonable period of time, either with a response or with a reviewed in light of experience since the policies were set.
reasonable explanation for the delay (some requests may be
particularly complex), and if this is a recurring event, IANA must
raise the issue with the IESG. Because of the problems caused by
delayed evaluations and assignments, the IESG should take
appropriate actions to ensure that the expert understands and
accepts his or her responsibilities, or appoint a new expert.
o The designated expert is not required to personally bear the Note that the well-known policies are not exclusive; there are
burden of evaluating and deciding all requests, but acts as a situations where a different policy might be more appropriate.
shepherd for the request, enlisting the help of others as
appropriate. In the case that a request is denied, and rejecting
the request is likely to be controversial, the expert should have
the support of other subject matter experts. That is, the expert
must be able to defend a decision to the community as a whole.
When a designated expert is used, the documentation should give clear 2.2.2. Using Multiple Policies in Combination
guidance to the designated expert, laying out criteria for performing
an evaluation and reasons for rejecting a request. In the case where
there are no specific documented criteria, the presumption should be
that a code point should be granted unless there is a compelling
reason to the contrary. Possible reasons to deny a request include
these:
o Scarcity of code points, where the finite remaining code points In some situations, it is necessary to define multiple registration
should be prudently managed, or when a request for a large number policies. For example, registrations through the normal IETF process
of code points is made, when a single code point is the norm. might use one policy, while registrations from outside the process
would have a different policy applied.
o Documentation is not of sufficient clarity to evaluate or ensure Thus, a particular registry might want to use a policy such as "RFC
interoperability. Required" or "IETF Review" sometimes, with a designated expert
checking a "Specification Required" policy at other times.
o The code point is needed for a protocol extension, but the The alternative to using a combination requires either that all
extension is not consistent with the documented (or generally requests come through RFCs or that requests in RFCs go through review
understood) architecture of the base protocol being extended, and by the designated expert, even though they already have IETF review
would be harmful to the protocol if widely deployed. It is not and consensus.
the intent that "inconsistencies" refer to minor differences "of a
personal preference nature". Instead, they refer to significant
differences such as inconsistencies with the underlying security
model, implying a change to the semantics of an existing message
type or operation, requiring unwarranted changes in deployed
systems (compared with alternate ways of achieving a similar
result), etc.
o The extension would cause problems with existing deployed systems. This can be documented in the IANA Considerations section when the
registry is created:
o The extension would conflict with one under active development by IANA is asked to create the registry "Fruit Access Flags" as a
the IETF, and having both would harm rather than foster sub-registry of "Fruit Parameters". New registrations will be
interoperability. permitted through either the IETF Review policy or the
Specification Required policy [BCP26].
3.4. Expert Reviews and the Document Lifecycle Such combinations will commonly use one of {Standards Action, IETF
Review, RFC Required} in combination with one of {Specification
Required, Expert Review}.
Review by the designated expert is necessarily done at a particular 2.3. Revising Existing Registries
point in time, and represents review of a particular version of the
document. Deciding when the review should take place is a question
of good judgment. And while re-reviews might be done when it's
acknowledged that the documentation of the registered item has
changed substantially, making sure that re-review happens requires
attention and care.
It is possible, through carelessness, accident, inattentiveness, or Updating the registration process for an already existing (previously
even willful disregard, that changes might be made after the created) namespace (whether created explicitly or implicitly) follows
designated expert's review and approval that would, if the document a process similar to that used when creating a new namespace. That
were re-reviewed, cause the expert not to approve the registration. is, a document is produced that makes reference to the existing
It is up to the IESG, with the token held by the responsible Area namespace and then provides detailed guidelines for handling
Director, to be alert to such situations and to recognize that such assignments in each individual namespace. Such documents are
changes need to be checked. normally processed as Best Current Practices (BCPs) [RFC2026].
4. Creating a Registry Example documents that updated the guidelines for managing (then)
pre-existing registries include: [RFC6195], [RFC3228], and [RFC3575].
Creating a registry involves describing the namespaces to be created, 3. Registering New Values in an Existing Registry
an initial set of assignments (if appropriate), and guidelines on how
future assignments are to be made.
Once a registry has been created, IANA records assignments that have 3.1. Documentation Requirements for Registrations
been made. The following labels describe the status of an individual
(or range) of assignments:
Private Use: Private use only (not assigned), as described in Often, documents request an assignment from an already existing
Section 4.1.1. namespace (one created by a previously published document).
Experimental: Available for general experimental use as described Such documents should clearly identify the namespace in which each
in [RFC3692]. IANA does not record specific assignments for value is to be registered. If the registration goes into a sub-
any particular use. registry, the author should clearly describe where the assignment or
registration should go. Use the exact namespace name as listed on
the IANA web page, and cite the RFC where the namespace is defined.
Unassigned: Not currently assigned, and available for assignment There is no need to mention what the assignment policy for new
via documented procedures. While it's generally clear that assignments is, as that should be clear from the references.
any values that are not registered are unassigned and
available for assignment, it is sometimes useful to
explicitly specify that situation. Note that this is
distinctly different from "Reserved".
Reserved: Not assigned and not available for assignment. When referring to an existing registry, providing a URL to precisely
Reserved values are held for special uses, such as to extend identify the registry is helpful. Such URLs, however, should usually
the namespace when it becomes exhausted. Note that this is be removed from the RFC prior to final publication, since IANA URLs
distinctly different from "Unassigned". are not guaranteed to be stable in the future. In cases where it is
important to include a URL in the document, IANA should concur on its
inclusion.
4.1. Well-Known IANA Policy Definitions For example, a document could contain something like this:
[TO BE REMOVED: This registration should be made in the Foobar
Operational Parameters registry, located at http://www.iana.org/
assignments/foobar-registry]
Each value requested should be given a unique reference. When the
value is numeric, use the notation: TBD1, TBD2, etc. Throughout the
document where an actual IANA-assigned value should be filled in, use
the "TBDx" notation. This helps ensure that the final RFC has the
correct assigned values inserted in all of the relevant places where
the value is expected to appear in the final document. For values
that are text strings, a specific name can be suggested. IANA will
normally assign the name, unless it conflicts with a name already in
use.
Normally, the values to be used are chosen by IANA and documents
should specify values of "TBD". However, in some cases, a value may
have been used for testing or in early implementations. In such
cases, it is acceptable to include text suggesting what specific
value should be used (together with the reason for the choice). For
example, one might include the text "the value XXX is suggested as it
is used in implementations". However, it should be noted that
suggested values are just that; IANA will attempt to assign them, but
may find that impossible, if the proposed number has already been
assigned for some other use.
For some registries, IANA has a long-standing policy prohibiting
assignment of names or codes on a vanity or organization-name basis.
For example, codes are always assigned sequentially unless there is a
strong reason for making an exception. Nothing in this document is
intended to change those policies or prevent their future
application.
The IANA Considerations section should summarize all of the IANA
actions, with pointers to the relevant sections elsewhere in the
document as appropriate. When multiple values are requested, it is
generally helpful to include a summary table. It is also helpful for
this table to be in the same format as it appears or will appear on
the IANA web site. For example:
Value Description Reference
-------- ------------------- ---------
TBD1 Foobar [[this RFC]]
Note: In cases where authors feel that including the full table is
too verbose or repetitive, authors should still include the table in
the draft, but may include a note asking that the table be removed
prior to publication of the final RFC.
As an example, the following text could be used to request assignment
of a DHCPv6 option number:
IANA has assigned an option code value of TBD1 to the DNS
Recursive Name Server option and an option code value of TBD2 to
the Domain Search List option from the DHCP option code space
defined in Section 24.3 of RFC 3315.
3.2. Updating Existing Registrations
Even after a number has been assigned, some types of registrations
contain additional information that may need to be updated over time.
For example, MIME media types, character sets, and language tags
typically include more information than just the registered value
itself, and may need things such as point-of-contact information,
security issues, pointers to updates, or literature references
updated.
In such cases, the document defining the namespace must clearly state
who is responsible for maintaining and updating a registration.
Depending on the registry, it may be appropriate to specify one or
more of:
o Letting registrants and/or nominated change controllers update
their own registrations, subject to the same constraints and
review as with new registrations.
o Allowing attachment of comments to the registration. This can be
useful in cases where others have significant objections to a
registration, but the author does not agree to change the
registration.
o Designating the IESG, a designated expert, or another entity as
having the right to change the registrant associated with a
registration and any requirements or conditions on doing so. This
is mainly to get around the problem when a registrant cannot be
reached in order to make necessary updates.
3.3. Overriding Registration Procedures
Experience has shown that the documented IANA considerations for
individual protocols do not always adequately cover the reality of
registry operation, or are not sufficiently clear. In addition,
documented IANA considerations are sometimes found to be too
stringent to allow even working group documents (for which there is
strong consensus) to perform a registration in advance of actual RFC
publication.
In order to allow assignments in such cases, the IESG is granted
authority to override registration procedures and approve assignments
on a case-by-case basis.
The intention here is not to overrule properly documented procedures,
or to obviate the need for protocols to properly document their IANA
considerations. Rather, it is to permit assignments in specific
cases where it is obvious that the assignment should just be made,
but updating the IANA process beforehand is too onerous.
When the IESG is required to take action as described in this
section, it is a strong indicator that the applicable registration
procedures should be updated, possibly in parallel with the work that
instigated it.
4. Well-Known Registration Policies
The following are some defined policies, most of which are in use The following are some defined policies, most of which are in use
today. These cover a range of typical policies that have been used today. These cover a range of typical policies that have been used
to describe the procedure for assigning new values in a namespace. to describe the procedure for assigning new values in a namespace.
It is not strictly required that documents use these terms; the It is not strictly required that documents use these terms; the
actual requirement is that the instructions to IANA be clear and actual requirement is that the instructions to IANA be clear and
unambiguous. However, use of these terms is strongly RECOMMENDED, unambiguous. However, use of these terms is strongly RECOMMENDED,
because their meanings are widely understood. The terms are fully because their meanings are widely understood. The terms are fully
explained in the following subsections. explained in the following subsections.
1. Private Use 1. Private Use
2. Experimental Use 2. Experimental Use
3. Hierarchical Allocation 3. Hierarchical Allocation
4. First Come First Served 4. First Come First Served
5. Expert Review 5. Expert Review
6. Specification Required 6. Specification Required
7. RFC Required 7. RFC Required
8. IETF Review 8. IETF Review
9. Standards Action 9. Standards Action
10. IESG Approval 10. IESG Approval
It should be noted that it often makes sense to partition a namespace It should be noted that it often makes sense to partition a namespace
into multiple categories, with assignments within each category into multiple categories, with assignments within each category
handled differently. Many protocols now partition namespaces into handled differently. Many protocols now partition namespaces into
two or more parts, with one range reserved for Private or two or more parts, with one range reserved for Private or
Experimental Use while other ranges are reserved for globally unique Experimental Use while other ranges are reserved for globally unique
assignments assigned following some review process. Dividing a assignments assigned following some review process. Dividing a
namespace into ranges makes it possible to have different policies in namespace into ranges makes it possible to have different policies in
place for different ranges and different use cases. place for different ranges and different use cases.
Similarly, it will often be useful to specify multiple policies in Similarly, it will often be useful to specify multiple policies in
parallel, with each policy being used under different circumstances. parallel, with each policy being used under different circumstances.
For more discussion of that topic, see Section 4.3. For more discussion of that topic, see Section 2.2.2.
Examples: Examples:
LDAP [RFC4520] LDAP [RFC4520]
TLS ClientCertificateType Identifiers [RFC5246] (as detailed in TLS ClientCertificateType Identifiers [RFC5246] (as detailed in
the subsections below) the subsections below)
Pseudowire Edge to Edge Emulation (PWE3) [RFC4446] Pseudowire Edge to Edge Emulation (PWE3) [RFC4446]
4.1.1. Policy: Private Use 4.1. Private Use
For private or local use only, with the type and purpose defined by For private or local use only, with the type and purpose defined by
the local site. No attempt is made to prevent multiple sites from the local site. No attempt is made to prevent multiple sites from
using the same value in different (and incompatible) ways. There is using the same value in different (and incompatible) ways. There is
no need for IANA to review such assignments (since IANA does not no need for IANA to review such assignments (since IANA does not
record them) and assignments are not generally useful for broad record them) and assignments are not generally useful for broad
interoperability. It is the responsibility of the sites making use interoperability. It is the responsibility of the sites making use
of the Private Use range to ensure that no conflicts occur (within of the Private Use range to ensure that no conflicts occur (within
the intended scope of use). the intended scope of use).
Examples: Examples:
skipping to change at page 12, line 47 skipping to change at page 14, line 14
For private or local use only, with the type and purpose defined by For private or local use only, with the type and purpose defined by
the local site. No attempt is made to prevent multiple sites from the local site. No attempt is made to prevent multiple sites from
using the same value in different (and incompatible) ways. There is using the same value in different (and incompatible) ways. There is
no need for IANA to review such assignments (since IANA does not no need for IANA to review such assignments (since IANA does not
record them) and assignments are not generally useful for broad record them) and assignments are not generally useful for broad
interoperability. It is the responsibility of the sites making use interoperability. It is the responsibility of the sites making use
of the Private Use range to ensure that no conflicts occur (within of the Private Use range to ensure that no conflicts occur (within
the intended scope of use). the intended scope of use).
Examples: Examples:
Site-specific options in DHCP [RFC2939] Site-specific options in DHCP [RFC2939]
Fibre Channel Port Type Registry [RFC4044] Fibre Channel Port Type Registry [RFC4044]
TLS ClientCertificateType Identifiers 224-255 [RFC5246] TLS ClientCertificateType Identifiers 224-255 [RFC5246]
4.1.2. Policy: Experimental Use 4.2. Experimental Use
Similar to private or local use only, with the purpose being to Similar to private or local use only, with the purpose being to
facilitate experimentation. See [RFC3692] for details. facilitate experimentation. See [RFC3692] for details.
Example: Example:
Experimental Values in IPv4, IPv6, ICMPv4, ICMPv6, UDP, and TCP Experimental Values in IPv4, IPv6, ICMPv4, ICMPv6, UDP, and TCP
Headers [RFC4727] Headers [RFC4727]
4.1.3. Policy: Hierarchical Allocation 4.3. Hierarchical Allocation
Delegated managers can assign values provided they have been given Delegated managers can assign values provided they have been given
control over that part of the namespace. IANA controls the higher control over that part of the namespace. IANA controls the higher
levels of the namespace according to one of the other policies. levels of the namespace according to one of the other policies.
Examples: Examples:
DNS names DNS names
Object Identifiers Object Identifiers
IP addresses IP addresses
4.1.4. Policy: First Come First Served 4.4. First Come First Served
Assignments are made to anyone on a first come, first served basis. Assignments are made to anyone on a first come, first served basis.
There is no substantive review of the request, other than to ensure There is no substantive review of the request, other than to ensure
that it is well-formed and doesn't duplicate an existing assignment. that it is well-formed and doesn't duplicate an existing assignment.
However, requests must include a minimal amount of clerical However, requests must include a minimal amount of clerical
information, such as a point of contact (including an email address) information, such as a point of contact (including an email address)
and a brief description of how the value will be used. Additional and a brief description of how the value will be used. Additional
information specific to the type of value requested may also need to information specific to the type of value requested may also need to
be provided, as defined by the namespace. For numbers, the exact be provided, as defined by the namespace. For numbers, the exact
value is generally assigned by IANA; with names, specific text value is generally assigned by IANA; with names, specific text
skipping to change at page 13, line 39 skipping to change at page 15, line 9
that it is well-formed and doesn't duplicate an existing assignment. that it is well-formed and doesn't duplicate an existing assignment.
However, requests must include a minimal amount of clerical However, requests must include a minimal amount of clerical
information, such as a point of contact (including an email address) information, such as a point of contact (including an email address)
and a brief description of how the value will be used. Additional and a brief description of how the value will be used. Additional
information specific to the type of value requested may also need to information specific to the type of value requested may also need to
be provided, as defined by the namespace. For numbers, the exact be provided, as defined by the namespace. For numbers, the exact
value is generally assigned by IANA; with names, specific text value is generally assigned by IANA; with names, specific text
strings can usually be requested. strings can usually be requested.
Examples: Examples:
SASL mechanism names [RFC4422] SASL mechanism names [RFC4422]
LDAP Protocol Mechanisms and LDAP Syntax [RFC4520] LDAP Protocol Mechanisms and LDAP Syntax [RFC4520]
4.1.5. Policy: Expert Review 4.5. Expert Review
(Sometimes also called "Designated Expert" in earlier editions of (Sometimes also called "Designated Expert" in earlier editions of
this document.) Review and approval by a designated expert is this document.) Review and approval by a designated expert is
required. The required documentation and review criteria for use by required. The required documentation and review criteria for use by
the designated expert should be provided when defining the registry. the designated expert should be provided when defining the registry.
For example, see Sections 6 and 7.2 in [RFC3748]. For example, see Sections 6 and 7.2 in [RFC3748].
It is particularly important, when using a designated expert, to give It is particularly important, when using a designated expert, to give
clear guidance to the expert, laying out criteria for performing an clear guidance to the expert, laying out criteria for performing an
evaluation and reasons for rejecting a request. When specifying a evaluation and reasons for rejecting a request. When specifying a
policy that involves a designated expert, the IANA Considerations policy that involves a designated expert, the IANA Considerations
SHOULD contain such guidance. It is also a good idea to include, SHOULD contain such guidance. It is also a good idea to include,
when possible, a sense of whether many registrations are expected when possible, a sense of whether many registrations are expected
skipping to change at page 14, line 11 skipping to change at page 15, line 31
It is particularly important, when using a designated expert, to give It is particularly important, when using a designated expert, to give
clear guidance to the expert, laying out criteria for performing an clear guidance to the expert, laying out criteria for performing an
evaluation and reasons for rejecting a request. When specifying a evaluation and reasons for rejecting a request. When specifying a
policy that involves a designated expert, the IANA Considerations policy that involves a designated expert, the IANA Considerations
SHOULD contain such guidance. It is also a good idea to include, SHOULD contain such guidance. It is also a good idea to include,
when possible, a sense of whether many registrations are expected when possible, a sense of whether many registrations are expected
over time, or if the registry is expected to be updated infrequently over time, or if the registry is expected to be updated infrequently
or in exceptional circumstances only. or in exceptional circumstances only.
Examples: Examples:
EAP Method Types [RFC3748] EAP Method Types [RFC3748]
HTTP Digest AKA algorithm versions [RFC4169] HTTP Digest AKA algorithm versions [RFC4169]
URI schemes [RFC4395] URI schemes [RFC4395]
GEOPRIV Location Types [RFC4589] GEOPRIV Location Types [RFC4589]
4.1.6. Policy: Specification Required 4.6. Specification Required
Review and approval by a Designated Expert is required, (as in Review and approval by a Designated Expert is required, (as in
Section 4.1.5) and the values and their meanings must be documented Section 4.5) and the values and their meanings must be documented in
in a permanent and readily available public specification, in a permanent and readily available public specification, in sufficient
sufficient detail so that interoperability between independent detail so that interoperability between independent implementations
implementations is possible. The Designated Expert will review the is possible. The Designated Expert will review the public
public specification and evaluate whether it is sufficiently clear to specification and evaluate whether it is sufficiently clear to allow
allow interoperable implementations. The intention behind "permanent interoperable implementations. The intention behind "permanent and
and readily available" is that a document can reasonably be expected readily available" is that a document can reasonably be expected to
to be findable and retrievable long after IANA assignment of the be findable and retrievable long after IANA assignment of the
requested value. Publication of an RFC is an ideal means of requested value. Publication of an RFC is an ideal means of
achieving this requirement, but Specification Required is intended to achieving this requirement, but Specification Required is intended to
also cover the case of a document published outside of the RFC path. also cover the case of a document published outside of the RFC path.
For RFC publication, the normal RFC review process is expected to For RFC publication, the normal RFC review process is expected to
provide the necessary review for interoperability, though the provide the necessary review for interoperability, though the
designated expert may be a particularly well-qualified person to designated expert may be a particularly well-qualified person to
perform such a review. perform such a review.
When specifying this policy, just use the term "Specification When specifying this policy, just use the term "Specification
Required". Some specifications have chosen to refer to it as "Expert Required". Some specifications have chosen to refer to it as "Expert
skipping to change at page 14, line 40 skipping to change at page 16, line 10
For RFC publication, the normal RFC review process is expected to For RFC publication, the normal RFC review process is expected to
provide the necessary review for interoperability, though the provide the necessary review for interoperability, though the
designated expert may be a particularly well-qualified person to designated expert may be a particularly well-qualified person to
perform such a review. perform such a review.
When specifying this policy, just use the term "Specification When specifying this policy, just use the term "Specification
Required". Some specifications have chosen to refer to it as "Expert Required". Some specifications have chosen to refer to it as "Expert
Review with Specification Required", and that only causes confusion. Review with Specification Required", and that only causes confusion.
Examples: Examples:
Diffserv-aware TE Bandwidth Constraints Model Identifiers Diffserv-aware TE Bandwidth Constraints Model Identifiers
[RFC4124] [RFC4124]
TLS ClientCertificateType Identifiers 64-223 [RFC5246] TLS ClientCertificateType Identifiers 64-223 [RFC5246]
ROHC Profile Identifiers [RFC5795] ROHC Profile Identifiers [RFC5795]
4.1.7. Policy: RFC Required 4.7. RFC Required
RFC publication suffices, as an IETF submission or in any other RFC publication suffices, as an IETF submission or in any other
stream (currently an RFC Editor Independent Submission [RFC5742] or stream (currently an RFC Editor Independent Submission [RFC5742] or
an RFC in the IRTF or IAB Stream). Unless otherwise specified, any an RFC in the IRTF or IAB Stream). Unless otherwise specified, any
type of RFC is sufficient (currently Standards Track, BCP, type of RFC is sufficient (currently Standards Track, BCP,
Informational, Experimental, Historic). Informational, Experimental, Historic).
4.1.8. Policy: IETF Review 4.8. IETF Review
(Formerly called "IETF Consensus" in the first edition of this (Formerly called "IETF Consensus" in the first edition of this
document.) New values are assigned only through RFCs in the IETF document.) New values are assigned only through RFCs in the IETF
Stream -- those that have been shepherded through the IESG as AD- Stream -- those that have been shepherded through the IESG as AD-
Sponsored or IETF working group Documents [RFC2026] [RFC5378]. The Sponsored or IETF working group Documents [RFC2026] [RFC5378]. The
intention is that the document and proposed assignment will be intention is that the document and proposed assignment will be
reviewed by the IESG and appropriate IETF working groups (or experts, reviewed by the IESG and appropriate IETF working groups (or experts,
if suitable working groups no longer exist) to ensure that the if suitable working groups no longer exist) to ensure that the
proposed assignment will not negatively impact interoperability or proposed assignment will not negatively impact interoperability or
otherwise extend IETF protocols in an inappropriate or damaging otherwise extend IETF protocols in an inappropriate or damaging
manner. manner.
To ensure adequate community review, such documents are shepherded To ensure adequate community review, such documents are shepherded
skipping to change at page 15, line 23 skipping to change at page 16, line 42
if suitable working groups no longer exist) to ensure that the if suitable working groups no longer exist) to ensure that the
proposed assignment will not negatively impact interoperability or proposed assignment will not negatively impact interoperability or
otherwise extend IETF protocols in an inappropriate or damaging otherwise extend IETF protocols in an inappropriate or damaging
manner. manner.
To ensure adequate community review, such documents are shepherded To ensure adequate community review, such documents are shepherded
through the IESG as AD-sponsored or working group documents with an through the IESG as AD-sponsored or working group documents with an
IETF Last Call. IETF Last Call.
Examples: Examples:
IPSECKEY Algorithm Types [RFC4025] IPSECKEY Algorithm Types [RFC4025]
Accounting-Auth-Method AVP values in DIAMETER [RFC4005] Accounting-Auth-Method AVP values in DIAMETER [RFC4005]
TLS Extension Types [RFC5246] TLS Extension Types [RFC5246]
4.1.9. Policy: Standards Action 4.9. Standards Action
Values are assigned only for Standards Track RFCs approved by the Values are assigned only for Standards Track RFCs approved by the
IESG. IESG.
Examples: Examples:
BGP message types [RFC4271] BGP message types [RFC4271]
Mobile Node Identifier option types [RFC4283] Mobile Node Identifier option types [RFC4283]
TLS ClientCertificateType Identifiers 0-63 [RFC5246] TLS ClientCertificateType Identifiers 0-63 [RFC5246]
DCCP Packet Types [RFC4340] DCCP Packet Types [RFC4340]
4.1.10. Policy: IESG Approval 4.10. IESG Approval
New assignments may be approved by the IESG. Although there is no New assignments may be approved by the IESG. Although there is no
requirement that the request be documented in an RFC, the IESG has requirement that the request be documented in an RFC, the IESG has
discretion to request documents or other supporting materials on a discretion to request documents or other supporting materials on a
case-by-case basis. case-by-case basis.
IESG Approval is not intended to be used often or as a "common case"; IESG Approval is not intended to be used often or as a "common case";
indeed, it has seldom been used in practice during the period RFC indeed, it has seldom been used in practice during the period RFC
2434 was in effect. Rather, it is intended to be available in 2434 was in effect. Rather, it is intended to be available in
conjunction with other policies as a fall-back mechanism in the case conjunction with other policies as a fall-back mechanism in the case
skipping to change at page 16, line 20 skipping to change at page 17, line 36
o The IESG can (and should) reject a request if another path for o The IESG can (and should) reject a request if another path for
registration is available that is more appropriate and there is no registration is available that is more appropriate and there is no
compelling reason not to use that path. compelling reason not to use that path.
o Before approving a request, the community should be consulted, via o Before approving a request, the community should be consulted, via
a "call for comments" that provides as much information as is a "call for comments" that provides as much information as is
reasonably possible about the request. reasonably possible about the request.
Examples: Examples:
IPv4 Multicast address assignments [RFC5771] IPv4 Multicast address assignments [RFC5771]
IPv4 IGMP Type and Code values [RFC3228] IPv4 IGMP Type and Code values [RFC3228]
Mobile IPv6 Mobility Header Type and Option values [RFC6275] Mobile IPv6 Mobility Header Type and Option values [RFC6275]
4.2. Best Practice for Selecting an Appropriate Policy 5. Designated Experts
The definitions above from "First Come First Served" to "Standards
Action" specify a range of policies in increasing order of
strictness:
4. First Come First Served:
No review, minimal documentation.
5. Expert Review:
Expert review, sufficient documentation for review.
6. Specification Required:
Expert review, significant, stable public documentation.
7. RFC Required:
Any RFC publication, IETF or a non-IETF Stream.
8. IETF Review:
RFC publication, IETF Stream only, but need not be Standards
Track.
9. Standards Action:
RFC publication, IETF Stream, Standards Track only.
In considering which of those policies to apply, it's important to
get the right balance of review and ease of registration. In many
cases, those needing to register items will not be IETF participants;
requests often come from other standards organizations, from
organizations not directly involved in standards, from ad-hoc
community work (from an open-source project, for example), and so on.
We must not make registration policies and procedures unnecessarily
difficult to navigate, unnecessarily costly (in terms of time and
other resources), nor unnecessarily subject to denial.
While it is sometimes necessary to restrict what gets registered (for
limited resources such as bits in a byte or numbers within a
relatively small range, or for items for which unsupported values can
be damaging to protocol operation), in many cases having items
registered is more important than putting restrictions on the
registration. A pattern of denial through overly strict review
criteria, or because of excessive cost in time and effort to get
through the process, discourages people from even attempting to
register their items. And failure to have in-use items registered
adversely affects the protocols in use on the Internet.
In particular, because policies 7 through 9 require involvement of
working groups, directorates, and/or communities of former working-
group participants to be actively involved and to support the effort,
requests frequently run into concerns that "it's not worth doing a
Standards-Track RFC for something this trivial," when, in fact, that
requirement was created by the working group in the first place, with
its selection of a Standards Action policy for the registry. Indeed,
publishing any RFC is costly, and a Standards Track RFC is especially
so, requiring a great deal of community time for review and
discussion, IETF-wide last call, involvement of the entire IESG as
well as concentrated time and review from the sponsoring AD, review
and action by IANA, and RFC-Editor processing.
Working groups and other document developers should use care in
selecting appropriate registration policies when their documents
create registries. They should select the least strict policy that
suits a registry's needs, and look for specific justification for
policies stricter than Specification Required. Examples of
situations that might merit RFC Required, IETF Review, or Standards
Action include the following.
o Registries of limited resources, such as bits in a byte (or in two
bytes, or four), or numbers in a limited range. In these cases,
allowing registrations that haven't been carefully reviewed and
agreed by community consensus could too quickly deplete the
allowable values.
o Registries for which thorough community review is necessary to
avoid extending or modifying the protocol in ways that could be
damaging. One example is in defining new command codes, as
opposed to options that use existing command codes: the former
might require a strict policy, where a more relaxed policy could
be adequate for the latter. Another example is in defining things
that change the semantics of existing operations.
There will be other cases, as well, of course; much assessment and
judgment is needed. And it will sometimes be the case that using
multiple policies in combination is appropriate (see Section 4.3).
It's not the intent here to put limits on the applicability of
particular registration policies, but to recommend laxity, rather
than strictness, in general, and to encourage document developers to
think carefully about each registry before deciding on policies.
The description in Section 4.1.10 of "IESG Approval" suggests that
the IESG "can (and should) reject a request if another path for
registration is available that is more appropriate and there is no
compelling reason not to use that path." The IESG should give
similar consideration to any registration policy more stringent than
Specification Required, asking for justification and ensuring that
more relaxed policies have been considered, and the strict policy is
the right one. This is a situation that will -- and should --
involve a substantive discussion between the IESG and the working
group, chairs, document editors, and/or document shepherd. The
important point, again, is not to relax the registration policy just
to get the document through quickly, but to carefully choose the
right policy for each registry.
Accordingly, document developers need to anticipate this and document
their considerations for selecting the specified policy. Ideally,
they should include that in the document. At the least, it should be
included in the shepherd writeup for the document, and in any case
the document shepherd should ensure that the selected policies have
been justified before sending the document to the IESG.
When specifications are revised, registration policies should be
reviewed in light of experience since the policies were set. It is
also possible to produce a small document at any time, which
"updates" the original specification and changes registration
policies. In either case, a policy can be relaxed or made more
strict, as appropriate to the actual situation.
Once again, it cannot be stressed enough that this must not be a
mechanical process, but one to which the document developers apply
thought, consideration, assessment, and judgment in choosing the
right policy for each registry.
The recommendations in this section apply whether the well-defined
policy names defined herein are used, or whether the document
contains other policy definitions. The point, again, is not to limit
registration policies, but to ensure that the policies selected are
appropriate, and that proper consideration has been given to the
level of strictness required by them.
4.3. Using Multiple Policies in Combination
It is often desirable to allow registrations through the normal IETF
process, and to also provide a mechanism for registration outside the
process. Thus, a particular registry might want to use a policy such
as "RFC Required" or "IETF Review" sometimes, with a designated
expert checking a "Specification Required" policy at other times.
Such combinations are frequently appropriate, and are encouraged.
The alternative to using a combination requires either that all
requests come through RFCs or that requests in RFCs go through review
by the designated expert, despite the review and consensus that RFCs
represent.
For example, if it is felt that IETF consensus will provide good
review for a particular registry, but we expect frequent
registrations from other SDOs and we do not want those other
organizations always to be required to go through the IETF RFC
process, we might put the following in the IANA Considerations
section when we create the registry:
IANA is asked to create the registry "Fruit Access Flags" as a
sub-registry of "Fruit Parameters". New registrations will be
permitted through either the IETF Review policy or the
Specification Required policy [BCP26].
Such combinations will commonly use one of {Standards Action, IETF
Review, RFC Required} in combination with one of {Specification
Required, Expert Review}.
4.4. What to Put in Documents That Create a Registry
The previous sections presented some issues that should be considered
in formulating a policy for assigning values in namespaces. It is
the working group and/or document author's job to formulate an
appropriate policy and specify it in the appropriate document. In
almost all cases, having an explicit "IANA Considerations" section is
appropriate. The following and later sections define what is needed
for the different types of IANA actions.
Documents that create a new namespace (or modify the definition of an
existing space) and that expect IANA to play a role in maintaining
that space (serving as a repository for registered values) MUST
provide clear instructions on details of the namespace. In
particular, instructions MUST include:
1. The name of the registry (or sub-registry) being created and/or
maintained.
The name will appear on the IANA web page and will be referred to
in future documents that need to allocate a value from the new
space. The full name (and abbreviation, if appropriate) should
be provided. It is highly desirable that the chosen name not be
easily confusable with the name of another registry. When
creating a sub-registry, the registry that it is a part of must
be clearly identified using its exact name (look it up, to be
sure). Providing a URL to precisely identify the registry is
helpful. Such URLs will be removed from the RFC prior to final
publication, but help to ensure that IANA will understand exactly
what is being requested. For example, a document could contain
something like this:
[TO BE REMOVED: This registration should be made in the Foobar
Operational Parameters registry, located at
http://www.iana.org/assignments/foobar-registry]
2. What information must be provided as part of a request in order
to assign a new value. This information may include the need to
document relevant security considerations, if any.
3. The review process that will apply to all future requests for a 5.1. The Motivation for Designated Experts
value from the namespace.
Note: When a designated expert is used, documents MUST NOT name IANA does not define registry policy itself; rather, it carries out
the designated expert in the document itself; instead, any policies that have been defined by others and published in RFCs. As
suggested names should be relayed to the appropriate Area part of that process, review of proposed registrations is often
Director at the time the document is sent to the IESG for appropriate.
approval. This is usually done in the document shepherd writeup.
If the request should also be reviewed on a specific public A common way to ensure such review is for a proposed registration to
mailing list (such as the media-types@iana.org for media types), be published as an RFC, as this ensures that the specification is
that mailing address should be specified. Note, however, that publicly and permanently available. It is particularly important if
when mailing lists are specified, the requirement for a any potential interoperability issues might arise. For example, some
designated expert MUST also be specified (see Section 3). assignments are not just assignments, but also involve an element of
protocol specification. A new option may define fields that need to
be parsed and acted on, which (if specified poorly) may not fit
cleanly with the architecture of other options or the base protocols
on which they are built.
If IANA is expected to make assignments without requiring an In some cases, however, the burden of publishing an RFC in order to
outside review, sufficient guidance MUST be provided so that the register a protocol element is excessive.
requests can be evaluated with minimal subjectivity.
4. The size, format, and syntax of registry entries. When creating However, it is generally still useful (and sometimes necessary) to
a new name/number space, authors must describe any technical discuss proposed registrations within the community, on a mailing
requirements on registry (and sub-registry) values (valid ranges list. Such a mailing list provides opportunity for public review
for integers, length limitations on strings, etc.) as well as the prior to assignment, and allows for a consultative process when
exact format in which registry values should be displayed. For registrants want help in understanding what a proper registration
number assignments, one should specify whether values are to be should contain.
recorded in decimal, hexadecimal, or some other format. For
strings, the encoding format should be specified (ASCII, UTF8,
etc.). Authors should also clearly specify what fields to record
in the registry.
5. Initial assignments and reservations. Clear instructions should While discussion on a mailing list can provide valuable technical
be provided to identify any initial assignments or registrations. feedback, opinions may vary and discussions may continue for some
In addition, any ranges that are to be reserved for "Private time without clear resolution. In addition, IANA cannot participate
Use", "Reserved", "Unassigned", etc. should be clearly indicated. in all of these mailing lists and cannot determine if or when such
discussions reach consensus. Therefore, IANA relies on a "designated
expert" for advice regarding the specific question of whether an
assignment should be made. The designated expert is an individual
who is responsible for carrying out an appropriate evaluation and
returning a recommendation to IANA.
When specifying the process for making future assignments, it is It should be noted that a key motivation for having designated
quite acceptable to pick one (or more) of the example policies listed experts is for the IETF to provide IANA with a subject matter expert
in Section 4.1 and refer to it by name. Indeed, this is the to whom the evaluation process can be delegated. IANA forwards
preferred mechanism in those cases where the sample policies provide requests for an assignment to the expert for evaluation, and the
the desired level of review. It is also acceptable to cite one of expert (after performing the evaluation) informs IANA as to whether
the above policies and include additional guidelines for what kind of or not to make the assignment or registration.
considerations should be taken into account by the review process.
For example, RADIUS [RFC3575] specifies the use of a Designated
Expert, but includes specific additional criteria the Designated
Expert should follow.
For example, a document could say something like this: It will often be useful to use a designated expert only some of the
time, as a supplement to other processes. For more discussion of
that topic, see Section 2.2.2.
--------------------------------------------------------------- 5.2. The Role of the Designated Expert
This document defines a new DHCP option, entitled "FooBar" (see
Section y), assigned a value of TBD1 from the DHCP Option space
[to be removed upon publication:
http://www.iana.org/assignments/bootp-dhcp-parameters]
[RFC2132] [RFC2939]:
Data
Tag Name Length Meaning
---- ---- ------ -------
TBD1 FooBar N FooBar server
The FooBar option also defines an 8-bit FooType field, for which The designated expert is responsible for initiating and coordinating
IANA is to create and maintain a new sub-registry entitled the appropriate review of an assignment request. The review may be
"FooType values" under the FooBar option. Initial values for the wide or narrow, depending on the situation and the judgment of the
DHCP FooBar FooType registry are given below; future assignments designated expert. This may involve consultation with a set of
are to be made through Expert Review [BCP26]. technology experts, discussion on a public mailing list, consultation
Assignments consist of a DHCP FooBar FooType name and its with a working group (or its mailing list if the working group has
associated value. disbanded), etc. Ideally, the designated expert follows specific
review criteria as documented with the protocol that creates or uses
the namespace. See the IANA Considerations sections of [RFC3748] and
[RFC3575] for specific examples.
Value DHCP FooBar FooType Name Definition Designated experts are expected to be able to defend their decisions
---- ------------------------ ---------- to the IETF community, and the evaluation process is not intended to
0 Reserved be secretive or bestow unquestioned power on the expert. Experts are
1 Frobnitz See Section y.1 expected to apply applicable documented review or vetting procedures,
2 NitzFrob See Section y.2 or in the absence of documented criteria, follow generally accepted
3-254 Unassigned norms such as those in Section 5.3.
255 Reserved
---------------------------------------------------------------
For examples of documents that provide detailed guidance to IANA on Section 3.2 discusses disputes and appeals in more detail.
the issue of assigning numbers, consult [RFC6195], [RFC3575],
[RFC3968], and [RFC4520].
4.5. Updating IANA Guidelines for Existing Registries Designated experts are appointed by the IESG (normally upon
recommendation by the relevant Area Director). They are typically
named at the time a document creating or updating a namespace is
approved by the IESG, but as experts originally appointed may later
become unavailable, the IESG will appoint replacements if necessary.
Updating the registration process for an already existing (previously For some registries, it has proven useful to have multiple designated
created) namespace (whether created explicitly or implicitly) follows experts. Sometimes those experts work together in evaluating a
a process similar to that used when creating a new namespace. That request, while in other cases additional experts serve as backups.
is, a document is produced that makes reference to the existing In cases of disagreement among those experts, it is the
namespace and then provides detailed guidelines for handling responsibility of those experts to make a single clear recommendation
assignments in each individual namespace. Such documents are to IANA. It is not appropriate for IANA to resolve disputes among
normally processed as Best Current Practices (BCPs) [RFC2026]. experts. In extreme situations, such as deadlock, the IESG may need
to step in to resolve the problem.
Example documents that updated the guidelines for managing (then) In registries where a pool of experts evaluates requests, the pool
pre-existing registries include: [RFC6195], [RFC3228], and [RFC3575]. should have a single chair responsible for defining how requests are
to be assigned to and reviewed by experts. In some cases, the expert
pool may consist of a primary and backups, with the backups involved
only when the primary expert is unavailable. In other cases, IANA
might assign requests to individual members in sequential or
approximate random order. In the event that IANA finds itself having
received conflicting advice from its experts, it is the
responsibility of the pool's chair to resolve the issue and provide
IANA with clear instructions.
5. Registering New Values in an Existing Registry Since the designated experts are appointed by the IESG, they may be
removed by the IESG.
5.1. What to Put in Documents When Registering Values 5.3. Designated Expert Reviews
Often, documents request an assignment from an already existing In the years since RFC 2434 was published and has been put to use,
namespace (one created by a previously published document). In such experience has led to the following observations:
cases:
o Documents should clearly identify the namespace in which each o A designated expert must respond in a timely fashion, normally
value is to be registered. If the registration goes into a sub- within a week for simple requests to a few weeks for more complex
registry, the author should clearly describe where the assignment ones. Unreasonable delays can cause significant problems for
or registration should go. It is helpful to use the *exact* those needing assignments, such as when products need code points
namespace name as listed on the IANA web page (please look it up, to ship. This is not to say that all reviews can be completed
and don't guess), and cite the RFC where the namespace is defined. under a firm deadline, but they must be started, and the requester
and IANA should have some transparency into the process if an
answer cannot be given quickly.
Note 1: There is no need to mention what the assignment policy for o If a designated expert does not respond to IANA's requests within
new assignments is, as that should be clear from the references. a reasonable period of time, either with a response or with a
reasonable explanation for the delay (some requests may be
particularly complex), and if this is a recurring event, IANA must
raise the issue with the IESG. Because of the problems caused by
delayed evaluations and assignments, the IESG should take
appropriate actions to ensure that the expert understands and
accepts his or her responsibilities, or appoint a new expert.
Note 2: When referring to an existing registry, providing a URL to o The designated expert is not required to personally bear the
precisely identify the registry is helpful. Such URLs, however, burden of evaluating and deciding all requests, but acts as a
should usually be removed from the RFC prior to final publication, shepherd for the request, enlisting the help of others as
since IANA URLs are not guaranteed to be stable in the future. In appropriate. In the case that a request is denied, and rejecting
cases where it is important to include a URL in the document, IANA the request is likely to be controversial, the expert should have
should concur on its inclusion. the support of other subject matter experts. That is, the expert
must be able to defend a decision to the community as a whole.
For example, a document could contain something like this: When a designated expert is used, the documentation should give clear
guidance to the designated expert, laying out criteria for performing
an evaluation and reasons for rejecting a request. In the case where
there are no specific documented criteria, the presumption should be
that a code point should be granted unless there is a compelling
reason to the contrary. Possible reasons to deny a request include
these:
[TO BE REMOVED: This registration should be made in the Foobar o Scarcity of code points, where the finite remaining code points
Operational Parameters registry, located at should be prudently managed, or when a request for a large number
http://www.iana.org/assignments/foobar-registry] of code points is made, when a single code point is the norm.
o Each value requested should be given a unique reference. When the o Documentation is not of sufficient clarity to evaluate or ensure
value is numeric, use the notation: TBD1, TBD2, etc. Throughout interoperability.
the document where an actual IANA-assigned value should be filled
in, use the "TBDx" notation. This helps ensure that the final RFC
has the correct assigned values inserted in all of the relevant
places where the value is expected to appear in the final
document. For values that are text strings, a specific name can
be suggested. IANA will normally assign the name, unless it
conflicts with a name already in use.
o Normally, the values to be used are chosen by IANA and documents o The code point is needed for a protocol extension, but the
should specify values of "TBD". However, in some cases, a value extension is not consistent with the documented (or generally
may have been used for testing or in early implementations. In understood) architecture of the base protocol being extended, and
such cases, it is acceptable to include text suggesting what would be harmful to the protocol if widely deployed. It is not
specific value should be used (together with the reason for the the intent that "inconsistencies" refer to minor differences "of a
choice). For example, one might include the text "the value XXX personal preference nature". Instead, they refer to significant
is suggested as it is used in implementations". However, it differences such as inconsistencies with the underlying security
should be noted that suggested values are just that; IANA will model, implying a change to the semantics of an existing message
attempt to assign them, but may find that impossible, if the type or operation, requiring unwarranted changes in deployed
proposed number has already been assigned for some other use. For systems (compared with alternate ways of achieving a similar
some registries, IANA has a long-standing policy prohibiting result), etc.
assignment of names or codes on a vanity or organization-name
basis. For example, codes are always assigned sequentially unless
there is a strong reason for making an exception. Nothing in this
document is intended to change those policies or prevent their
future application.
o The IANA Considerations section should summarize all of the IANA o The extension would cause problems with existing deployed systems.
actions, with pointers to the relevant sections elsewhere in the
document as appropriate. When multiple values are requested, it
is generally helpful to include a summary table. It is also
helpful for this table to be in the same format as it appears or
will appear on the IANA web site. For example:
Value Description Reference o The extension would conflict with one under active development by
-------- ------------------- --------- the IETF, and having both would harm rather than foster
TBD1 Foobar [[this RFC]] interoperability.
Note: In cases where authors feel that including the full table is When a designated expert is used, documents MUST NOT name the
too verbose or repetitive, authors should still include the table designated expert in the document itself; instead, any suggested
in the draft, but may include a note asking that the table be names should be relayed to the appropriate Area Director at the time
removed prior to publication of the final RFC. the document is sent to the IESG for approval. This is usually done
in the document shepherd writeup.
As an example, the following text could be used to request assignment If the request should also be reviewed on a specific public mailing
of a DHCPv6 option number: list, its address should be specified.
IANA has assigned an option code value of TBD1 to the DNS 5.4. Expert Reviews and the Document Lifecycle
Recursive Name Server option and an option code value of TBD2 to
the Domain Search List option from the DHCP option code space
defined in Section 24.3 of RFC 3315.
5.2. Updating Registrations Review by the designated expert is necessarily done at a particular
point in time, and represents review of a particular version of the
document. Deciding when the review should take place is a question
of good judgment. And while re-reviews might be done when it's
acknowledged that the documentation of the registered item has
changed substantially, making sure that re-review happens requires
attention and care.
Registrations are a request to assign a new value, including the It is possible, through carelessness, accident, inattentiveness, or
related information needed to evaluate and document the request. even willful disregard, that changes might be made after the
Even after a number has been assigned, some types of registrations designated expert's review and approval that would, if the document
contain additional information that may need to be updated over time. were re-reviewed, cause the expert not to approve the registration.
For example, MIME media types, character sets, and language tags, It is up to the IESG, with the token held by the responsible Area
etc. typically include more information than just the registered Director, to be alert to such situations and to recognize that such
value itself. Example information can include point-of-contact changes need to be checked.
information, security issues, pointers to updates, literature
references, etc. In such cases, the document defining the namespace
must clearly state who is responsible for maintaining and updating a
registration. In different cases, it may be appropriate to specify
one or more of the following:
o Let the author update the registration, subject to the same 6. Well-Known Registration Status Terminology
constraints and review as with new registrations.
o Allow some mechanism to attach comments to the registration, for The following labels describe the status of an individual (or range)
cases where others have significant objections to claims in a of assignments:
registration, but the author does not agree to change the
registration.
o Designate the IESG, a designated expert, or another entity as Private Use: Private use only (not assigned), as described in
having the right to change the registrant associated with a Section 4.1.
registration and any requirements or conditions on doing so. This
is mainly to get around the problem when a registrant cannot be
reached in order to make necessary updates.
5.3. Overriding Registration Procedures Experimental: Available for general experimental use as described
in [RFC3692]. IANA does not record specific assignments for
any particular use.
Since RFC 2434 was published, experience has shown that the Unassigned: Not currently assigned, and available for assignment
documented IANA considerations for individual protocols do not always via documented procedures. While it's generally clear that
adequately cover the reality after the protocol is deployed. For any values that are not registered are unassigned and
example, many older routing protocols do not have documented, available for assignment, it is sometimes useful to
detailed IANA considerations. In addition, documented IANA explicitly specify that situation. Note that this is
considerations are sometimes found to be too stringent to allow even distinctly different from "Reserved".
working group documents (for which there is strong consensus) to
obtain code points from IANA in advance of actual RFC publication.
In other cases, the documented procedures are unclear or neglected to
cover all the cases. In order to allow assignments in individual
cases where there is strong IETF consensus that an allocation should
go forward, but the documented procedures do not support such an
assignment, the IESG is granted authority to approve assignments in
such cases. The intention is not to overrule properly documented
procedures, or to obviate the need for protocols to properly document
their IANA considerations. Instead, the intention is to permit
assignments in individual cases where it is obvious that the
assignment should just be made, but updating the IANA process just to
assign a particular code point is viewed as too heavy a burden.
In general, the IETF would like to see deficient IANA registration Reserved: Not assigned and not available for assignment. Reserved
procedures for a namespace revised through the IETF standards values are held for special uses, such as to extend the
process, but not at the cost of unreasonable delay for needed namespace when it becomes exhausted. Note that this is
assignments. If the IESG has had to take the action in this section, distinctly different from "Unassigned".
it is a strong indicator that the IANA registration procedures should
be updated, possibly in parallel with ongoing protocol work.
6. Documentation References in IANA Registries 7. Documentation References in IANA Registries
Usually, registries and registry entries include references to Usually, registries and registry entries include references to
documentation (RFCs or other documents). The purpose of these documentation (RFCs or other documents). The purpose of these
references is to provide pointers for implementors to find details references is to provide pointers for implementors to find details
necessary for implementation, NOT to simply note what document necessary for implementation, NOT to simply note what document
created the registry or entry. Therefore: created the registry or entry. Therefore:
o If a document registers an item that is defined and explained o If a document registers an item that is defined and explained
elsewhere, the registered reference should be to that document, elsewhere, the registered reference should be to that document,
and not to the document that is merely performing the and not to the document that is merely performing the
skipping to change at page 26, line 36 skipping to change at page 22, line 46
than just "[RFC9876]". than just "[RFC9876]".
o For documentation of a new registry, the reference should provide o For documentation of a new registry, the reference should provide
information about the registry itself, not just a pointer to the information about the registry itself, not just a pointer to the
creation of it. Useful information includes the purpose of the creation of it. Useful information includes the purpose of the
registry, a rationale for its creation, documentation of the registry, a rationale for its creation, documentation of the
process and policy for new registrations, guidelines for new process and policy for new registrations, guidelines for new
registrants or designated experts, and other such related registrants or designated experts, and other such related
information. information.
7. What to Do in "bis" Documents 8. What to Do in "bis" Documents
We often produce a new edition of an RFC, which obsoletes the On occaison, an RFC is issued that obsoletes a previous edition of
previous edition (we sometimes call these "bis" documents, such as the same document. We sometimes call these "bis" documents, such as
when RFC 9876 is updated by draft-ietf-foo-rfc9876bis). When the when RFC 9876 is updated by draft-ietf-foo-rfc9876bis. When the
original document created registries and/or registered entries, there original document created registries and/or registered entries, there
is a question of how to handle the IANA Considerations section in the is a question of how to handle the IANA Considerations section in the
"bis" document. "bis" document.
If the registrations specify the original document as a reference, If the registrations specify the original document as a reference,
those registrations should be updated to point to the current (not those registrations should be updated to point to the current (not
obsolete) documentation for those items. Usually, that will mean obsolete) documentation for those items. Usually, that will mean
changing the reference to be the "bis" document. changing the reference to be the "bis" document.
For example, suppose RFC 9876 registered the "BANANA" flag in the For example, suppose RFC 9876 registered the "BANANA" flag in the
"Fruit Access Flags" registry, and the documentation for that flag is "Fruit Access Flags" registry, and the documentation for that flag is
in Section 3.2. The current registry might look, in part, like this: in Section 3.2.
Name Description Reference The current registry might look, in part, like this:
-------- ------------------- ---------
BANANA Flag for bananas [RFC9876], Section 3.2 Name Description Reference
-------- ------------------- ---------
BANANA Flag for bananas [RFC9876], Section 3.2
If draft-ietf-foo-rfc9876bis obsoletes RFC 9876 and, because of some If draft-ietf-foo-rfc9876bis obsoletes RFC 9876 and, because of some
rearrangement, now documents the flag in Section 4.1.2, the IANA rearrangement, now documents the flag in Section 4.1.2, the IANA
Considerations of the bis document might contain text such as this: Considerations of the bis document might contain text such as this:
IANA is asked to change the registration information for the IANA is asked to change the registration information for the
BANANA flag in the "Fruit Access Flags" registry to the following: BANANA flag in the "Fruit Access Flags" registry to the following:
Name Description Reference Name Description Reference
-------- ------------------- --------- -------- ------------------- ---------
BANANA Flag for bananas [[this RFC]], Section 4.2.1 BANANA Flag for bananas [[this RFC]], Section 4.2.1
In many cases, if there are a number of registered references to the In many cases, if there are a number of registered references to the
original RFC and the document organization has not changed the original RFC and the document organization has not changed the
registered section numbering much, it may simply be reasonable to do registered section numbering much, it may simply be reasonable to do
this: this:
Because this document obsoletes RFC 9876, IANA is asked to change Because this document obsoletes RFC 9876, IANA is asked to change
all registration information that references [RFC9876] to instead all registration information that references [RFC9876] to instead
reference [[this RFC]]. reference [[this RFC]].
If information for registered items has been or is being moved to If information for registered items has been or is being moved to
other documents, then, of course, the registration information should other documents, then, of course, the registration information should
be changed to point to those other documents. In no case is it be changed to point to those other documents. In no case is it
reasonable to leave documentation pointers to the obsoleted document reasonable to leave documentation pointers to the obsoleted document
for any registries or registered items that are still in current use. for any registries or registered items that are still in current use.
8. Miscellaneous Issues 9. Miscellaneous Issues
8.1. When There Are No IANA Actions
9.1. When There Are No IANA Actions
Before an Internet-Draft can be published as an RFC, IANA needs to Before an Internet-Draft can be published as an RFC, IANA needs to
know what actions (if any) it needs to perform. Experience has shown know what actions (if any) it needs to perform. Experience has shown
that it is not always immediately obvious whether a document has no that it is not always immediately obvious whether a document has no
IANA actions, without reviewing the document in some detail. In IANA actions, without reviewing the document in some detail. In
order to make it clear to IANA that it has no actions to perform (and order to make it clear to IANA that it has no actions to perform (and
that the author has consciously made such a determination), such that the author has consciously made such a determination), such
documents should include an IANA Considerations section that states: documents should include an IANA Considerations section that states:
This document has no IANA actions. This document has no IANA actions.
skipping to change at page 28, line 31 skipping to change at page 24, line 40
considered of no value once the document has been approved, and may considered of no value once the document has been approved, and may
be removed before archival publication. This choice should be made be removed before archival publication. This choice should be made
clear in the draft, for example, by including a sentence such as clear in the draft, for example, by including a sentence such as
[RFC Editor: please remove this section prior to publication.] [RFC Editor: please remove this section prior to publication.]
or or
[RFC Editor: please do not remove this section.] [RFC Editor: please do not remove this section.]
8.2. Namespaces Lacking Documented Guidance 9.2. Namespaces Lacking Documented Guidance
For all existing RFCs that either explicitly or implicitly rely on For all existing RFCs that either explicitly or implicitly rely on
IANA to evaluate assignments without specifying a precise evaluation IANA to evaluate assignments without specifying a precise evaluation
policy, IANA (in consultation with the IESG) will continue to decide policy, IANA (in consultation with the IESG) will continue to decide
what policy is appropriate. Changes to existing policies can always what policy is appropriate. Changes to existing policies can always
be initiated through the normal IETF consensus process. be initiated through the normal IETF consensus process.
All future RFCs that either explicitly or implicitly rely on IANA to All future RFCs that either explicitly or implicitly rely on IANA to
register or otherwise manage namespace assignments MUST provide register or otherwise manage namespace assignments MUST provide
guidelines for managing the namespace. guidelines for managing the namespace.
8.3. After-the-Fact Registrations 9.3. After-the-Fact Registrations
Occasionally, IANA becomes aware that an unassigned value from a Occasionally, IANA becomes aware that an unassigned value from a
managed namespace is in use on the Internet or that an assigned value managed namespace is in use on the Internet or that an assigned value
is being used for a different purpose than originally registered. is being used for a different purpose than originally registered.
IANA will not condone such misuse; procedures of the type described IANA will not condone such misuse; procedures of the type described
in this document MUST be applied to such cases. In the absence of in this document MUST be applied to such cases. In the absence of
specifications to the contrary, values may only be reassigned for a specifications to the contrary, values may only be reassigned for a
different purpose with the consent of the original assignee (when different purpose with the consent of the original assignee (when
possible) and with due consideration of the impact of such a possible) and with due consideration of the impact of such a
reassignment. In cases of likely controversy, consultation with the reassignment. In cases of likely controversy, consultation with the
IESG is advised. IESG is advised.
8.4. Reclaiming Assigned Values 9.4. Reclaiming Assigned Values
Reclaiming previously assigned values for reuse is tricky, because Reclaiming previously assigned values for reuse is tricky, because
doing so can lead to interoperability problems with deployed systems doing so can lead to interoperability problems with deployed systems
still using the assigned values. Moreover, it can be extremely still using the assigned values. Moreover, it can be extremely
difficult to determine the extent of deployment of systems making use difficult to determine the extent of deployment of systems making use
of a particular value. However, in cases where the namespace is of a particular value. However, in cases where the namespace is
running out of unassigned values and additional ones are needed, it running out of unassigned values and additional ones are needed, it
may be desirable to attempt to reclaim unused values. When may be desirable to attempt to reclaim unused values. When
reclaiming unused values, the following (at a minimum) should be reclaiming unused values, the following (at a minimum) should be
considered: considered:
skipping to change at page 29, line 38 skipping to change at page 25, line 46
is not widely used, and the need to reclaim the value outweighs is not widely used, and the need to reclaim the value outweighs
the cost of a hostile reclamation. In any case, IESG Approval is the cost of a hostile reclamation. In any case, IESG Approval is
needed in this case. needed in this case.
o It may be appropriate to write up the proposed action and solicit o It may be appropriate to write up the proposed action and solicit
comments from relevant user communities. In some cases, it may be comments from relevant user communities. In some cases, it may be
appropriate to write an RFC that goes through a formal IETF appropriate to write an RFC that goes through a formal IETF
process (including IETF Last Call) as was done when DHCP reclaimed process (including IETF Last Call) as was done when DHCP reclaimed
some of its "Private Use" options [RFC3942]. some of its "Private Use" options [RFC3942].
8.5. Contact Person vs Assignee or Owner 9.5. Contact Person vs Assignee or Owner
Many registries include designation of a technical or administrative Many registries include designation of a technical or administrative
contact associated with each entry. Often, this is recorded as contact associated with each entry. Often, this is recorded as
contact information for an individual. It is unclear, though, what contact information for an individual. It is unclear, though, what
role the individual has with respect to the registration: is this role the individual has with respect to the registration: is this
item registered on behalf of the individual, the company the item registered on behalf of the individual, the company the
individual worked for, or perhaps another organization the individual individual worked for, or perhaps another organization the individual
was acting for? was acting for?
This matters because some time later, when the individual has changed This matters because some time later, when the individual has changed
jobs or roles, and perhaps can no longer be contacted, someone might jobs or roles, and perhaps can no longer be contacted, someone might
want to update the registration. IANA has no way to know what want to update the registration. IANA has no way to know what
company, organization, or individual should be allowed to take the company, organization, or individual should be allowed to take the
registration over. For registrations rooted in RFCs, the stream registration over. For registrations rooted in RFCs, the stream
owner (such as the IESG or the IAB) can make an overriding decision. owner (such as the IESG or the IAB) can make an overriding decision.
But in other cases, there is no recourse. But in other cases, there is no recourse.
Registries can include, in addition to a "Contact" field, an Registries can include, in addition to a "Contact" field, an
"Assignee" or "Owner" field that can be used to address this "Assignee" or "Owner" field that can be used to address this
situation, giving IANA clear guidance as to the actual owner of the situation, giving IANA clear guidance as to the actual owner of the
registration. Alternatively, organizations can put an organizational registration. Alternatively, organizations can put an organizational
role into the "Contact" field in order to make their ownership clear. role into the "Contact" field in order to make their ownership clear.
8.6. Closing or Obsoleting a Registry 9.6. Closing or Obsoleting a Registry
[[anchor2: This section needs to be resolved before publication.]] [[This section needs to be resolved before publication.]]
8.7. BCP 78/79 Issues in Registries 9.7. BCP 78/79 Issues in Registries
[[anchor3: This section needs to be resolved before publication.]] [[This section needs to be resolved before publication, but I'm not
sure anything's needed here after all. ]]
9. Appeals 10. Appeals
Appeals of registration decisions made by IANA can be made using the Appeals of registration decisions made by IANA can be made using the
normal IETF appeals process as described in Section 6.5 of [RFC2026]. normal IETF appeals process as described in Section 6.5 of [RFC2026].
Specifically, appeals should be directed to the IESG, followed (if Specifically, appeals should be directed to the IESG, followed (if
necessary) by an appeal to the IAB, etc. necessary) by an appeal to the IAB, etc.
10. Mailing Lists 11. Mailing Lists
All IETF mailing lists associated with evaluating or discussing All IETF mailing lists associated with evaluating or discussing
assignment requests as described in this document are subject to assignment requests as described in this document are subject to
whatever rules of conduct and methods of list management are whatever rules of conduct and methods of list management are
currently defined by Best Current Practices or by IESG decision. currently defined by Best Current Practices or by IESG decision.
11. Security Considerations 12. Security Considerations
Information that creates or updates a registration needs to be Information that creates or updates a registration needs to be
authenticated and authorized. IANA updates registries according to authenticated and authorized. IANA updates registries according to
instructions in published RFCs and from the IESG. It also may accept instructions in published RFCs and from the IESG. It also may accept
clarifications from document authors, relevant working group chairs, clarifications from document authors, relevant working group chairs,
Designated Experts, and mail list participants, too. Designated Experts, and mail list participants, too.
Information concerning possible security vulnerabilities of a Information concerning possible security vulnerabilities of a
protocol may change over time. Likewise, security vulnerabilities protocol may change over time. Likewise, security vulnerabilities
related to how an assigned number is used may change as well. As new related to how an assigned number is used may change as well. As new
skipping to change at page 31, line 16 skipping to change at page 27, line 14
An analysis of security issues is generally required for all An analysis of security issues is generally required for all
protocols that make use of parameters (data types, operation codes, protocols that make use of parameters (data types, operation codes,
keywords, etc.) used in IETF protocols or registered by IANA. Such keywords, etc.) used in IETF protocols or registered by IANA. Such
security considerations are usually included in the protocol document security considerations are usually included in the protocol document
[RFC3552]. It is the responsibility of the IANA considerations [RFC3552]. It is the responsibility of the IANA considerations
associated with a particular registry to specify what (if any) associated with a particular registry to specify what (if any)
security considerations must be provided when assigning new values, security considerations must be provided when assigning new values,
and the process for reviewing such claims. and the process for reviewing such claims.
12. Changes Relative to Earlier Editions of BCP 26 13. To-Do List; resolve and remove before requesting publication
12.1. 2012: Changes in This Document Relative to RFC 5226 Just was speaking with someone at the IANA office hours. I was
looking through the 5226bis draft and there is nothing in there about
how to deprecate values in registries. Might be something good to
add.
14. Changes Relative to Earlier Editions of BCP 26
14.1. 2013: Changes in This Document Relative to RFC 5226
Significant additions: Significant additions:
o Added Section 3.4, Expert Reviews and the Document Lifecycle o Added Section 5.4, Expert Reviews and the Document Lifecycle
o Moved well-known policies into a separate section for each, o Moved well-known policies into a separate section for each,
subsections of Section 4.1. subsections of Section 4.
o Added Section 4.2, Best Practice for Selecting an Appropriate o Added Section 2.2, Best Practice for Selecting an Appropriate
Policy. Policy.
o Added Section 4.3, Using Multiple Policies in Combination. o Added Section 2.2.2, Using Multiple Policies in Combination.
o Added Section 6, Documentation References in IANA Registries o Added Section 7, Documentation References in IANA Registries
o Added Section 7, What to Do in "bis" Documents o Added Section 8, What to Do in "bis" Documents
o Added Section 8.5, Contact Person vs Assignee or Owner o Added Section 9.5, Contact Person vs Assignee or Owner
o Added Section 8.6, Closing or Obsoleting a Registry o Added Section 9.6, Closing or Obsoleting a Registry
o Added Section 8.7, BCP 78/79 Issues in Registries o Added Section 9.7, BCP 78/79 Issues in Registries
Clarifications and such: Clarifications and such:
o Some reorganization -- moved text around for clarity and easier
reading.
o Made clarifications about identification of IANA registries and o Made clarifications about identification of IANA registries and
use of URLs for them. use of URLs for them.
o Clarified the distinction between "Unassigned" and "Reserved". o Clarified the distinction between "Unassigned" and "Reserved".
o Made some clarifications in "Expert Review" about instructions to o Made some clarifications in "Expert Review" about instructions to
the designated expert. the designated expert.
o Made some clarifications in "Specification Required" about how to o Made some clarifications in "Specification Required" about how to
declare this policy. declare this policy.
o Assorted minor clarifications and editorial changes throughout. o Assorted minor clarifications and editorial changes throughout.
12.2. 2008: Changes in RFC 5226 Relative to RFC 2434 14.2. 2008: Changes in RFC 5226 Relative to RFC 2434
Changes include: Changes include:
o Major reordering of text to expand descriptions and to better o Major reordering of text to expand descriptions and to better
group topics such as "updating registries" vs. "creating new group topics such as "updating registries" vs. "creating new
registries", in order to make it easier for authors to find the registries", in order to make it easier for authors to find the
text most applicable to their needs. text most applicable to their needs.
o Numerous editorial changes to improve readability. o Numerous editorial changes to improve readability.
o Changed the term "IETF Consensus" to "IETF Review" and added more o Changed the term "IETF Consensus" to "IETF Review" and added more
clarifications. History has shown that people see the words "IETF clarifications. History has shown that people see the words "IETF
Consensus" (without consulting the actual definition) and are Consensus" (without consulting the actual definition) and are
quick to make incorrect assumptions about what the term means in quick to make incorrect assumptions about what the term means in
the context of IANA Considerations. the context of IANA Considerations.
skipping to change at page 33, line 5 skipping to change at page 28, line 54
RFC 2026 appeals path is used. RFC 2026 appeals path is used.
o Added a section about reclaiming unused value. o Added a section about reclaiming unused value.
o Added a section on after-the-fact registrations. o Added a section on after-the-fact registrations.
o Added a section indicating that mailing lists used to evaluate o Added a section indicating that mailing lists used to evaluate
possible assignments (such as by a Designated Expert) are subject possible assignments (such as by a Designated Expert) are subject
to normal IETF rules. to normal IETF rules.
13. Acknowledgments 15. Acknowledgments
13.1. Acknowledgments for This Document (2012)
15.1. Acknowledgments for This Document (2013)
Thomas Narten and Harald Tveit Alvestrand edited the two earlier Thomas Narten and Harald Tveit Alvestrand edited the two earlier
editions of this document (RFCs 2434 and 5226), and Thomas continues editions of this document (RFCs 2434 and 5226), and Thomas continues
his role in this third edition. Most of the text from RFC 5226 his role in this third edition. Much of the text from RFC 5226
remains in this edition. remains in this edition.
13.2. Acknowledgments from the second edition (2008) Special thanks to Mark Nottingham for thoroughly reviewing the
document and reorganizing the text for better organization and
readability.
15.2. Acknowledgments from the second edition (2008)
The original acknowledgments section in RFC 5226 was: The original acknowledgments section in RFC 5226 was:
This document has benefited from specific feedback from Jari Arkko, This document has benefited from specific feedback from Jari Arkko,
Marcelo Bagnulo Braun, Brian Carpenter, Michelle Cotton, Spencer Marcelo Bagnulo Braun, Brian Carpenter, Michelle Cotton, Spencer
Dawkins, Barbara Denny, Miguel Garcia, Paul Hoffman, Russ Housley, Dawkins, Barbara Denny, Miguel Garcia, Paul Hoffman, Russ Housley,
John Klensin, Allison Mankin, Blake Ramsdell, Mark Townsley, Magnus John Klensin, Allison Mankin, Blake Ramsdell, Mark Townsley, Magnus
Westerlund, and Bert Wijnen. Westerlund, and Bert Wijnen.
13.3. Acknowledgments from the first edition (1998) 15.3. Acknowledgments from the first edition (1998)
The original acknowledgments section in RFC 2434 was: The original acknowledgments section in RFC 2434 was:
Jon Postel and Joyce Reynolds provided a detailed explanation on what Jon Postel and Joyce Reynolds provided a detailed explanation on what
IANA needs in order to manage assignments efficiently, and patiently IANA needs in order to manage assignments efficiently, and patiently
provided comments on multiple versions of this document. Brian provided comments on multiple versions of this document. Brian
Carpenter provided helpful comments on earlier versions of the Carpenter provided helpful comments on earlier versions of the
document. One paragraph in the Security Considerations section was document. One paragraph in the Security Considerations section was
borrowed from [RFC4288]. borrowed from [RFC4288].
14. References 16. References
14.1. Normative References 16.1. Normative References
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119, March 1997. Requirement Levels", BCP 14, RFC 2119, March 1997.
14.2. Informative References 16.2. Informative References
[RFC0791] Postel, J., "Internet Protocol", STD 5, RFC 791, [RFC0791] Postel, J., "Internet Protocol", STD 5, RFC 791, September
September 1981. 1981.
[RFC2026] Bradner, S., "The Internet Standards Process -- Revision [RFC2026] Bradner, S., "The Internet Standards Process -- Revision
3", BCP 9, RFC 2026, October 1996. 3", BCP 9, RFC 2026, October 1996.
[RFC2132] Alexander, S. and R. Droms, "DHCP Options and BOOTP Vendor [RFC2132] Alexander, S. and R. Droms, "DHCP Options and BOOTP Vendor
Extensions", RFC 2132, March 1997. Extensions", RFC 2132, March 1997.
[RFC2860] Carpenter, B., Baker, F., and M. Roberts, "Memorandum of [RFC2860] Carpenter, B., Baker, F. and M. Roberts, "Memorandum of
Understanding Concerning the Technical Work of the Understanding Concerning the Technical Work of the
Internet Assigned Numbers Authority", RFC 2860, June 2000. Internet Assigned Numbers Authority", RFC 2860, June 2000.
[RFC2929] Eastlake, D., Brunner-Williams, E. and B. Manning, "Domain
Name System (DNS) IANA Considerations", RFC 2929,
September 2000.
[RFC2939] Droms, R., "Procedures and IANA Guidelines for Definition [RFC2939] Droms, R., "Procedures and IANA Guidelines for Definition
of New DHCP Options and Message Types", BCP 43, RFC 2939, of New DHCP Options and Message Types", BCP 43, RFC 2939,
September 2000. September 2000.
[RFC3228] Fenner, B., "IANA Considerations for IPv4 Internet Group [RFC3228] Fenner, B., "IANA Considerations for IPv4 Internet Group
Management Protocol (IGMP)", BCP 57, RFC 3228, Management Protocol (IGMP)", BCP 57, RFC 3228, February
February 2002. 2002.
[RFC3232] Reynolds, J., "Assigned Numbers: RFC 1700 is Replaced by [RFC3232] Reynolds, J., "Assigned Numbers: RFC 1700 is Replaced by
an On-line Database", RFC 3232, January 2002. an On-line Database", RFC 3232, January 2002.
[RFC3552] Rescorla, E. and B. Korver, "Guidelines for Writing RFC [RFC3552] Rescorla, E. and B. Korver, "Guidelines for Writing RFC
Text on Security Considerations", BCP 72, RFC 3552, Text on Security Considerations", BCP 72, RFC 3552, July
July 2003. 2003.
[RFC3575] Aboba, B., "IANA Considerations for RADIUS (Remote [RFC3575] Aboba, B., "IANA Considerations for RADIUS (Remote
Authentication Dial In User Service)", RFC 3575, Authentication Dial In User Service)", RFC 3575, July
July 2003. 2003.
[RFC3692] Narten, T., "Assigning Experimental and Testing Numbers [RFC3692] Narten, T., "Assigning Experimental and Testing Numbers
Considered Useful", BCP 82, RFC 3692, January 2004. Considered Useful", BCP 82, RFC 3692, January 2004.
[RFC3748] Aboba, B., Blunk, L., Vollbrecht, J., Carlson, J., and H. [RFC3748] Aboba, B., Blunk, L., Vollbrecht, J., Carlson, J. and H.
Levkowetz, "Extensible Authentication Protocol (EAP)", Levkowetz, "Extensible Authentication Protocol (EAP)", RFC
RFC 3748, June 2004. 3748, June 2004.
[RFC3942] Volz, B., "Reclassifying Dynamic Host Configuration [RFC3942] Volz, B., "Reclassifying Dynamic Host Configuration
Protocol version 4 (DHCPv4) Options", RFC 3942, Protocol version 4 (DHCPv4) Options", RFC 3942, November
November 2004. 2004.
[RFC3968] Camarillo, G., "The Internet Assigned Number Authority [RFC3968] Camarillo, G., "The Internet Assigned Number Authority
(IANA) Header Field Parameter Registry for the Session (IANA) Header Field Parameter Registry for the Session
Initiation Protocol (SIP)", BCP 98, RFC 3968, Initiation Protocol (SIP)", BCP 98, RFC 3968, December
December 2004. 2004.
[RFC4005] Calhoun, P., Zorn, G., Spence, D., and D. Mitton, [RFC4005] Calhoun, P., Zorn, G., Spence, D. and D. Mitton, "Diameter
"Diameter Network Access Server Application", RFC 4005, Network Access Server Application", RFC 4005, August 2005.
August 2005.
[RFC4025] Richardson, M., "A Method for Storing IPsec Keying [RFC4025] Richardson, M., "A Method for Storing IPsec Keying
Material in DNS", RFC 4025, March 2005. Material in DNS", RFC 4025, March 2005.
[RFC4044] McCloghrie, K., "Fibre Channel Management MIB", RFC 4044, [RFC4044] McCloghrie, K., "Fibre Channel Management MIB", RFC 4044,
May 2005. May 2005.
[RFC4124] Le Faucheur, F., "Protocol Extensions for Support of [RFC4124] Le Faucheur, F., "Protocol Extensions for Support of
Diffserv-aware MPLS Traffic Engineering", RFC 4124, Diffserv-aware MPLS Traffic Engineering", RFC 4124, June
June 2005. 2005.
[RFC4169] Torvinen, V., Arkko, J., and M. Naslund, "Hypertext [RFC4169] Torvinen, V., Arkko, J. and M. Naslund, "Hypertext
Transfer Protocol (HTTP) Digest Authentication Using Transfer Protocol (HTTP) Digest Authentication Using
Authentication and Key Agreement (AKA) Version-2", Authentication and Key Agreement (AKA) Version-2", RFC
RFC 4169, November 2005. 4169, November 2005.
[RFC4271] Rekhter, Y., Li, T., and S. Hares, "A Border Gateway [RFC4271] Rekhter, Y., Li, T. and S. Hares, "A Border Gateway
Protocol 4 (BGP-4)", RFC 4271, January 2006. Protocol 4 (BGP-4)", RFC 4271, January 2006.
[RFC4283] Patel, A., Leung, K., Khalil, M., Akhtar, H., and K. [RFC4283] Patel, A., Leung, K., Khalil, M., Akhtar, H. and K.
Chowdhury, "Mobile Node Identifier Option for Mobile IPv6 Chowdhury, "Mobile Node Identifier Option for Mobile IPv6
(MIPv6)", RFC 4283, November 2005. (MIPv6)", RFC 4283, November 2005.
[RFC4288] Freed, N. and J. Klensin, "Media Type Specifications and [RFC4288] Freed, N. and J. Klensin, "Media Type Specifications and
Registration Procedures", BCP 13, RFC 4288, December 2005. Registration Procedures", BCP 13, RFC 4288, December 2005.
[RFC4301] Kent, S. and K. Seo, "Security Architecture for the [RFC4301] Kent, S. and K. Seo, "Security Architecture for the
Internet Protocol", RFC 4301, December 2005. Internet Protocol", RFC 4301, December 2005.
[RFC4340] Kohler, E., Handley, M., and S. Floyd, "Datagram [RFC4340] Kohler, E., Handley, M. and S. Floyd, "Datagram Congestion
Congestion Control Protocol (DCCP)", RFC 4340, March 2006. Control Protocol (DCCP)", RFC 4340, March 2006.
[RFC4395] Hansen, T., Hardie, T., and L. Masinter, "Guidelines and [RFC4395] Hansen, T., Hardie, T. and L. Masinter, "Guidelines and
Registration Procedures for New URI Schemes", BCP 35, Registration Procedures for New URI Schemes", BCP 35, RFC
RFC 4395, February 2006. 4395, February 2006.
[RFC4422] Melnikov, A. and K. Zeilenga, "Simple Authentication and [RFC4422] Melnikov, A. and K. Zeilenga, "Simple Authentication and
Security Layer (SASL)", RFC 4422, June 2006. Security Layer (SASL)", RFC 4422, June 2006.
[RFC4446] Martini, L., "IANA Allocations for Pseudowire Edge to Edge [RFC4446] Martini, L., "IANA Allocations for Pseudowire Edge to Edge
Emulation (PWE3)", BCP 116, RFC 4446, April 2006. Emulation (PWE3)", BCP 116, RFC 4446, April 2006.
[RFC4520] Zeilenga, K., "Internet Assigned Numbers Authority (IANA) [RFC4520] Zeilenga, K., "Internet Assigned Numbers Authority (IANA)
Considerations for the Lightweight Directory Access Considerations for the Lightweight Directory Access
Protocol (LDAP)", BCP 64, RFC 4520, June 2006. Protocol (LDAP)", BCP 64, RFC 4520, June 2006.
skipping to change at page 36, line 9 skipping to change at page 31, line 53
[RFC4727] Fenner, B., "Experimental Values In IPv4, IPv6, ICMPv4, [RFC4727] Fenner, B., "Experimental Values In IPv4, IPv6, ICMPv4,
ICMPv6, UDP, and TCP Headers", RFC 4727, November 2006. ICMPv6, UDP, and TCP Headers", RFC 4727, November 2006.
[RFC5246] Dierks, T. and E. Rescorla, "The Transport Layer Security [RFC5246] Dierks, T. and E. Rescorla, "The Transport Layer Security
(TLS) Protocol Version 1.2", RFC 5246, August 2008. (TLS) Protocol Version 1.2", RFC 5246, August 2008.
[RFC5378] Bradner, S. and J. Contreras, "Rights Contributors Provide [RFC5378] Bradner, S. and J. Contreras, "Rights Contributors Provide
to the IETF Trust", BCP 78, RFC 5378, November 2008. to the IETF Trust", BCP 78, RFC 5378, November 2008.
[RFC5742] Alvestrand, H. and R. Housley, "IESG Procedures for [RFC5742] Alvestrand, H. and R. Housley, "IESG Procedures for
Handling of Independent and IRTF Stream Submissions", Handling of Independent and IRTF Stream Submissions", BCP
BCP 92, RFC 5742, December 2009. 92, RFC 5742, December 2009.
[RFC5771] Cotton, M., Vegoda, L., and D. Meyer, "IANA Guidelines for [RFC5771] Cotton, M., Vegoda, L. and D. Meyer, "IANA Guidelines for
IPv4 Multicast Address Assignments", BCP 51, RFC 5771, IPv4 Multicast Address Assignments", BCP 51, RFC 5771,
March 2010. March 2010.
[RFC5795] Sandlund, K., Pelletier, G., and L-E. Jonsson, "The RObust [RFC5795] Sandlund, K., Pelletier, G. and L-E. Jonsson, "The RObust
Header Compression (ROHC) Framework", RFC 5795, Header Compression (ROHC) Framework", RFC 5795, March
March 2010. 2010.
[RFC6195] Eastlake, D., "Domain Name System (DNS) IANA [RFC6195] Eastlake, D., "Domain Name System (DNS) IANA
Considerations", BCP 42, RFC 6195, March 2011. Considerations", BCP 42, RFC 6195, March 2011.
[RFC6275] Perkins, C., Johnson, D., and J. Arkko, "Mobility Support [RFC6275] Perkins, C., Johnson, D. and J. Arkko, "Mobility Support
in IPv6", RFC 6275, July 2011. in IPv6", RFC 6275, July 2011.
[RFC6709] Carpenter, B., Aboba, B., and S. Cheshire, "Design [RFC6709] Carpenter, B., Aboba, B. and S. Cheshire, "Design
Considerations for Protocol Extensions", RFC 6709, Considerations for Protocol Extensions", RFC 6709,
September 2012. September 2012.
Authors' Addresses Authors' Addresses
Michelle Cotton Michelle Cotton, Manager, IANA Services
Internet Assigned Numbers Authority (IANA) Internet Corporation for Assigned Names and Numbers
4676 Admiralty Way, Suite 330 12025 Waterfront Drive, Suite 300
Marina del Rey, CA 90292 Los Angeles, CA 90094-2536
USA US
Phone: +1 310 301 5812 Phone: +1 310 301 5812
Email: michelle.cotton@icann.org Email: michelle.cotton@icann.org
Barry Leiba Barry Leiba
Huawei Technologies Huawei Technologies
Phone: +1 646 827 0648 Phone: +1 646 827 0648
Email: barryleiba@computer.org Email: barryleiba@computer.org
URI: http://internetmessagingtechnology.org/ URI: http://internetmessagingtechnology.org/
skipping to change at page 37, line 4 skipping to change at page 32, line 40
Phone: +1 310 301 5812 Phone: +1 310 301 5812
Email: michelle.cotton@icann.org Email: michelle.cotton@icann.org
Barry Leiba Barry Leiba
Huawei Technologies Huawei Technologies
Phone: +1 646 827 0648 Phone: +1 646 827 0648
Email: barryleiba@computer.org Email: barryleiba@computer.org
URI: http://internetmessagingtechnology.org/ URI: http://internetmessagingtechnology.org/
Thomas Narten Thomas Narten
IBM Corporation IBM Corporation
3039 Cornwallis Ave., PO Box 12195 - BRQA/502 3039 Cornwallis Ave., PO Box 12195 - BRQA/502
Research Triangle Park, NC 27709-2195 Research Triangle Park, NC 27709-2195
USA US
Phone: +1 919 254 7798 Phone: +1 919 254 7798
Email: narten@us.ibm.com Email: narten@us.ibm.com
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