wdiff draft-leiba-cotton-iana-5226bis-01.txt draft-leiba-cotton-iana-5226bis-02.txt

Network Working Group M. Cotton
Internet-Draft Internet Assigned Numbers ICANN
BCP: 26 B. Leiba
Obsoletes: 5226 (if approved) Authority (IANA)
Intended status: BCP B. Leiba
Expires: April 5, 2013 Huawei Technologies
Intended status: Best Current Practice T. Narten
Expires: September 28, 2013 IBM Corporation
October 2, 2012
March 29, 2013

Guidelines for Writing an IANA Considerations Section in RFCs
draft-leiba-cotton-iana-5226bis-01
draft-leiba-cotton-iana-5226bis-02

Abstract

Many protocols make use of identifiers consisting points of extensibility that use constants and
other well-known values. Even after a protocol has been defined and
deployment has begun, new values may need
to be assigned (such as for
a new option type in DHCP, or a new encryption or authentication
transform for IPsec). identify various protocol parameters. To ensure that such quantities have consistent the values
used in these fields do not have conflicting uses, and interpretations across all implementations, to promote
interoperability, their
assignment must be administered allocation is often coordinated by a central
authority. For IETF protocols, that role is provided filled by the Internet
Assigned Numbers Authority (IANA).

In order for IANA to

To manage a given namespace prudently, it IANA needs
guidelines guidance describing
the conditions under which new values can should be
assigned or assigned, as well as
when and how modifications to existing values can be made. If
IANA is expected to play This
document defines a role in framework for the management documentation of a namespace,
IANA must be these
guidelines by specification authors, in order to assure that the
guidance given to IANA is clear and concise instructions describing that
role. This document discusses addresses the various issues that should be considered
are likely in
formulating a policy for assigning values to a namespace and provides
guidelines for authors on the specific text that must be included in
documents that place demands on IANA. operation of a registry.

This document is the third edition, and obsoletes RFC 5226.

Status of this Memo

This Internet-Draft is submitted in full conformance with the
provisions of BCP 78 and BCP 79.

Internet-Drafts are working documents of the Internet Engineering
Task Force (IETF). Note that other groups may also distribute
working documents as Internet-Drafts. The list of current Internet-
Drafts is at http://datatracker.ietf.org/drafts/current/.

Internet-Drafts are draft documents valid for a maximum of six months
and may be updated, replaced, or obsoleted by other documents at any
time. It is inappropriate to use Internet-Drafts as reference
material or to cite them other than as "work in progress."

This Internet-Draft will expire on April 5, September 28, 2013.

This document is subject to BCP 78 and the IETF Trust's Legal
Provisions Relating to IETF Documents
(http://trustee.ietf.org/license-info) (http://trustee.ietf.org/
license-info) in effect on the date of publication of this document.
Please review these documents carefully, as they describe your rights
and restrictions with respect to this document. Code Components
extracted from this document must include Simplified BSD License text
as described in Section 4.e of the Trust Legal Provisions and are
provided without warranty as described in the Simplified BSD License.

Table of Contents

1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 5 3
1.1. Terminology Used In This Document . . . . . . . . . . . . 5 3
2. Why Management of a Namespace May Be Necessary Creating and Revising Registries . . . . . . . . 6
3. Designated Experts . . . . . . . 3
2.1. Documentation Requirements for Registries . . . . . . . . 4
2.2. Defining an Appropriate Registry Policy . . . . . . . 7
3.1. The Motivation for Designated Experts . . 6
2.2.1. Using the Well-Known Registration Policies . . . . . . 8
2.2.2. Using Multiple Policies in Combination . . 7
3.2. The Role of the Designated Expert . . . . . . 9
2.3. Revising Existing Registries . . . . . . 8
3.3. Designated Expert Reviews . . . . . . . . . 10
3. Registering New Values in an Existing Registry . . . . . . . 9
3.4. Expert Reviews and the Document Lifecycle . 10
3.1. Documentation Requirements for Registrations . . . . . . . 10
4. Creating a Registry
3.2. Updating Existing Registrations . . . . . . . . . . . . . 12
3.3. Overriding Registration Procedures . . . . . . . . . . . . 11
4.1. 12
4. Well-Known IANA Policy Definitions Registration Policies . . . . . . . . . . . . . 11
4.1.1. Policy: . . 13
4.1. Private Use . . . . . . . . . . . . . . . . . 12
4.1.2. Policy: . . . . . . 13
4.2. Experimental Use . . . . . . . . . . . . . . . 13
4.1.3. Policy: . . . . . . 14
4.3. Hierarchical Allocation . . . . . . . . . . . 13
4.1.4. Policy: . . . . . . 14
4.4. First Come First Served . . . . . . . . . . . 13
4.1.5. Policy: . . . . . . 14
4.5. Expert Review . . . . . . . . . . . . . . . . 13
4.1.6. Policy: . . . . . . 15
4.6. Specification Required . . . . . . . . . . . . 14
4.1.7. Policy: . . . . . . 15
4.7. RFC Required . . . . . . . . . . . . . . . . . 14
4.1.8. Policy: . . . . . . 16
4.8. IETF Review . . . . . . . . . . . . . . . . . 15
4.1.9. Policy: . . . . . . 16
4.9. Standards Action . . . . . . . . . . . . . . . 15
4.1.10. Policy: . . . . . . 16
4.10. IESG Approval . . . . . . . . . . . . . . . . 15
4.2. Best Practice for Selecting an Appropriate Policy . . . . 16
4.3. Using Multiple Policies in Combination . . 17
5. Designated Experts . . . . . . . . 19
4.4. What to Put in Documents That Create a Registry . . . . . 19
4.5. Updating IANA Guidelines for Existing Registries . . . . . 22
5. Registering New Values in an Existing Registry . . . . 17
5.1. The Motivation for Designated Experts . . . . 23
5.1. What to Put in Documents When Registering Values . . . . . 23 . 17
5.2. Updating Registrations The Role of the Designated Expert . . . . . . . . . . . . 18
5.3. Designated Expert Reviews . . . . . . . . . 24
5.3. Overriding Registration Procedures . . . . . . . 19
5.4. Expert Reviews and the Document Lifecycle . . . . . 25 . . . 21
6. Well-Known Registration Status Terminology . . . . . . . . . . 21
7. Documentation References in IANA Registries . . . . . . . . . 26
7. 22
8. What to Do in "bis" Documents . . . . . . . . . . . . . . . . 26
8. 22
9. Miscellaneous Issues . . . . . . . . . . . . . . . . . . . . . 27
8.1. 23
9.1. When There Are No IANA Actions . . . . . . . . . . . . . . 27
8.2. 23
9.2. Namespaces Lacking Documented Guidance . . . . . . . . . . 28
8.3. 24
9.3. After-the-Fact Registrations . . . . . . . . . . . . . . . 28
8.4. 24
9.4. Reclaiming Assigned Values . . . . . . . . . . . . . . . . 29
8.5. 25
9.5. Contact Person vs Assignee or Owner . . . . . . . . . . . 29
8.6. 25
9.6. Closing or Obsoleting a Registry . . . . . . . . . . . . . 30
8.7. 26
9.7. BCP 78/79 Issues in Registries . . . . . . . . . . . . . . 30
9. 26
10. Appeals . . . . . . . . . . . . . . . . . . . . . . . . . . . 30
10. 26
11. Mailing Lists . . . . . . . . . . . . . . . . . . . . . . . . 30
11. 26
12. Security Considerations . . . . . . . . . . . . . . . . . . . 30
12. 26
13. To-Do List; resolve and remove before requesting publication . 27
14. Changes Relative to Earlier Editions of BCP 26 . . . . . . . . 31
12.1. 2012: 27
14.1. 2013: Changes in This Document Relative to RFC 5226 . . . 31
12.2. 27
14.2. 2008: Changes in RFC 5226 Relative to RFC 2434 . . . . . . 32
13. 28
15. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . 33
13.1. 28
15.1. Acknowledgments for This Document (2012) . (2013) . . . . . . . . 33
13.2. 28
15.2. Acknowledgments from the second edition (2008) . . . . . . 33
13.3. 29
15.3. Acknowledgments from the first edition (1998) . . . . . . 33
14. 29
16. References . . . . . . . . . . . . . . . . . . . . . . . . . . 33
14.1. 29
16.1. Normative References . . . . . . . . . . . . . . . . . . . 33
14.2. 29
16.2. Informative References . . . . . . . . . . . . . . . . . . 33 29
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 36 32

1. Introduction

Many protocols make use of fields points of extensibility that contain use constants and other
well-known values (such as the Protocol field in the IP header
[RFC0791] and MIME media types [RFC4288]). Even after a protocol has
been defined and deployment has begun, new values may need
to be
assigned (such as a new option type in DHCP [RFC2132] or a new
encryption or authentication transform for IPsec [RFC4301]). identify various protocol parameters. To ensure that such the values
used in these fields do not have consistent values conflicting uses, and interpretations in
different implementations, to promote
interoperability, their assignment must be administered allocation is often coordinated by a central
authority. For IETF protocols, that role is provided filled by the Internet
Assigned Numbers Authority (IANA) [RFC2860].

The Protocol field in the IP header [RFC0791] and MIME media types
[RFC4288] are two examples of such coordinations.

In this document, we call the set range of possible values for such a
field a "namespace"; its actual value may be a text string, a number, or
another kind of value. "namespace". The binding or association of a specific value
with a particular purpose within a namespace is called an assignment
(or, variously: an assigned number (or number, assigned value, or sometimes a "code point",
"protocol constant", or "protocol parameter"). Each assignment The act of a
value in a namespace assignment
is called a registration.

In order for IANA to registration, and it takes place in the context of a
registry.

To manage a given namespace prudently, it IANA needs
guidelines guidance describing
the conditions under which new values should be
assigned or assigned, as well as
when (and how) and how modifications to existing values can be made. This
document provides guidelines to authors on what sort defines a framework for the documentation of
text should be added to their documents these
guidelines by specification authors, in order to provide IANA
clear guidelines, and it reviews issues assure that should be considered in
formulating an appropriate policy for assigning numbers the
guidance given to name
spaces.

Not all namespaces require centralized administration. In some
cases, it IANA is possible to delegate a namespace in such a way that
further assignments can be made independently clear 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. As another example, Object Identifiers (OIDs) as defined
by addresses the ITU various issues that
are also delegated [RFC3232]; IANA manages likely in the subtree
rooted at "iso.org.dod.internet" (1.3.6.1) . When operation of a namespace registry.

Typically, this information is
delegated, the scope recorded in a dedicated section of IANA is limited to the parts of
specification with the namespace
where IANA has authority. title "IANA Considerations".

1.1. Terminology Used In This Document

The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
"SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this
document are to be interpreted as described in RFC 2119 [RFC2119].
For this document, "the specification" as used by RFC 2119 refers to
the processing of protocol documents within the IETF standards
process.

2. Why Management of a Namespace May Be Necessary

One issue to consider in managing a namespace is its size. If the
space is small Creating and limited in size, assignments must be made
carefully to prevent exhaustion of the space. If the space is
essentially unlimited, on the other hand, potential exhaustion will
probably not be Revising Registries
Defining a practical concern at all. Even when registry involves describing the space is
essentially unlimited, however, it is usually desirable to have at
least a minimal review prior namespace(s) to assignment in order to:

o prevent the hoarding of or unnecessary wasting of values. For
example, if the space consists of text strings, it may be
desirable to prevent entities from obtaining large sets
created, listing an initial set of strings
that correspond to desirable names (existing company names, for
example).

o provide a sanity check that the request actually makes sense assignments (if appropriate), and
is necessary. Experience has shown that some level of minimal
review from a subject matter expert is useful to prevent
documenting guidelines on how future assignments in cases where the request is malformed or not
actually needed (for example, an existing assignment for an
essentially equivalent service already exists).

A second consideration is whether it makes sense are to delegate be made.

Before defining a registry, however, consider delegating the
namespace in some manner. This route should be pursued when
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
potential interoperability issues, assigned numbers can safely be
given out to anyone without any subjective review.

In such cases,
IANA can make assignments directly, provided that IANA is given
specific instructions on what types of requests it should grant, and
what information must be provided as part of a well-formed request
for an assigned number.

3. Designated Experts

3.1. The Motivation for Designated Experts

It should be noted that IANA does particular, not create or define assignment
policy itself; rather, it carries out policies that have been defined
by others and published all namespaces require a registry; in RFCs. IANA must some cases,
assignments can be given a set of
guidelines that allow it to make allocation decisions with minimal
subjectivity made independently and without requiring any technical expertise with
respect to the protocols that make use of a registry. no further (central)
coordination. In many cases, some review of prospective allocations is appropriate,
and the question becomes who should perform the review and what is
the purpose of the review. One might think that an IETF working
group familiar with the namespace at hand should be consulted. In
practice, however, working groups eventually disband, so they cannot
be considered a permanent evaluator. It is also possible for
namespaces to be created through individual submission documents, Domain Name System, for
which no working group is ever formed.

One way to ensure community review of prospective example, IANA only
deals with assignments is to
have the requester submit a document for publication as an RFC. Such
an action helps ensure that at the specification is publicly and
permanently available, and it allows some review of higher levels, while subdomains are
administered by the specification
prior organization to publication and assignment of which the requested code points.
This space has been
delegated. When a namespace is delegated in this manner, the preferred way scope
of ensuring review, and IANA is particularly
important if any potential interoperability issues can arise. For
example, some assignments are not just assignments, but also involve
an element of protocol specification. A new option may define fields
that need limited 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 parts of publishing an RFC in order to
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 namespace where IANA has
authority.

2.1. Documentation Requirements for media types) or on a more general mailing
list (such as Registries

Documents that of a current or former IETF working group). Such
a mailing list provides create 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
feedback, opinions may vary and discussions may continue for some
time without clear resolution. In addition, IANA cannot participate
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 namespace (or modify the specific question definition of whether an
assignment should be made. The designated expert is an individual
who is responsible for carrying out an appropriate evaluation
existing space) and
returning a recommendation to IANA.

It should be noted that a key motivation for having designated
experts is for the IETF to provide IANA with a subject matter expert
to whom the evaluation process can be delegated. IANA forwards
requests for an assignment to the expert for evaluation, and the
expert (after performing the evaluation) informs expect IANA as to whether
or not to make the assignment or registration.

It will often be useful to use play a designated expert only some of the
time, role in maintaining
that space (serving as a supplement to other processes. For more discussion of
that topic, see Section 4.3.

3.2. The Role of the Designated Expert

The designated expert is responsible repository for initiating and coordinating
the appropriate review of an assignment request. The review may be
wide or narrow, depending registered values) MUST
provide clear instructions on details of the situation and namespace, either in the judgment
IANA Considerations section, or referenced from it.

In particular, such instructions MUST include:

The name of the
designated expert. registry (or sub-registry)
This may involve consultation with a set of
technology experts, discussion name will appear 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] web page and
[RFC3575] for examples that have been done for specific namespaces.

Designated experts are expected to will be able referred to defend their decisions
in future documents that need to allocate a value from the IETF community, and the evaluation process new
space. The full name (and abbreviation, if appropriate) should be
provided. It is highly desirable that the chosen name not intended to be secretive or bestow unquestioned power on the expert. Experts are
expected to apply applicable documented review or vetting procedures,
or in
easily confused with the absence name of documented criteria, follow generally accepted
norms such as those in Section 3.3.

Section 5.2 discusses disputes and appeals in more detail.

Designated experts are appointed by the IESG (normally upon
recommendation by the relevant Area Director). They are typically
named at the time a document another registry.

When creating or updating a namespace is
approved by the IESG, but as experts originally appointed may later
become unavailable, sub-registry, the IESG will appoint replacements if necessary.

For some registries, it has proven useful to have multiple designated
experts. Sometimes those experts work together in evaluating a
request, while in other cases additional experts serve as backups.

In cases of disagreement among those experts, registry that it is the
responsibility of those experts to make a single clear recommendation
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 part of experts evaluates requests, the pool
should have a single chair responsible for defining how requests are
to
must 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 identified using its experts, full name, exactly as it is the
responsibility of appears in
the pool's chair IANA registry list.

Providing a URL to resolve precisely identify the issue and provide registry helps IANA with clear instructions.

Since
understand the designated experts request. Such URLs are appointed by the IESG, they may be usually removed by the IESG.

3.3. Designated Expert Reviews

In from the years since
RFC 2434 was published and has been put to use,
experience has led to the following observations:

o A designated expert must respond in a timely fashion, normally
within a week for simple requests prior to final publication.

For example, a few weeks for more complex
ones. Unreasonable delays can cause significant problems for
those needing assignments, such as when products need code points
to ship. document could contain something like this:

[TO BE REMOVED: This is not to say that all reviews can be completed
under a firm deadline, but they must be started, and the requester
and IANA registration 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
a reasonable period of time, either with a response or with a
reasonable explanation for made in the delay (some requests Foobar
Operational Parameters registry, located at http://www.iana.org
/assignments/foobar-registry]

Required information for registrations

This information 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, include the IESG should take
appropriate actions need to ensure that the expert understands and
accepts his or her responsibilities, or appoint a new expert.

o document relevant
Security Considerations, if any.

Applicable review process

The designated expert is not required review process that will apply to personally bear the
burden of evaluating and deciding all requests, but acts as a
shepherd future requests for the request, enlisting the help of others as
appropriate. In the case that a request is denied,
registration. See Section 2.2.

Size, format and rejecting
the request is likely to be controversial, the expert should have
the support syntax 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
guidance registry entries

What fields to record in the designated expert, laying out criteria for performing
an evaluation registry., and reasons any technical
requirements upon registry entries (e.g., valid ranges for rejecting a request. In the case where
there are no specific documented criteria,
integers, length limitations on strings, etc.) as well as the presumption should be
that a code point
exact format in which registry values 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 displayed. For
numeric assignments, one should be prudently managed, or when a request for a large number
of code points is made, when a single code point is the norm.

o Documentation is not of sufficient clarity specify whether values are to evaluate or ensure
interoperability.

o The code point is needed for a protocol extension, but the
extension is not consistent with the documented (or generally
understood) architecture of the base protocol being extended, and
would be harmful to the protocol if widely deployed. It is not
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.

o The extension would conflict with one under active development by
the IETF, and having both would harm rather than foster
interoperability.

3.4. Expert Reviews and the Document Lifecycle

Review by the designated expert is necessarily done at a particular
point
recorded in time, and represents review of a particular version of the
document. Deciding when decimal, hexadecimal, or some other format. For
strings, the review encoding format 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 specified (ASCII, UTF8,
etc.).

Initial assignments and care.

It is possible, through carelessness, accident, inattentiveness, reservations

Any initial assignments or
even willful disregard, that changes might be made after the
designated expert's review and approval that would, if the document
were re-reviewed, cause the expert not to approve the registration.
It is up to the IESG, with the token held by the responsible Area
Director, registrations to be alert to such situations and to recognize included. In
addition, any ranges that such
changes need are to be checked.

4. Creating reserved for "Private Use",
"Reserved", "Unassigned", etc. should be indicated.

For example, a Registry

Creating document might specify a new registry involves describing the namespaces to be created,
an initial set by including:

---------------------------------------------------------------

X. IANA Considerations

This document defines a new DHCP option, entitled "FooBar" (see
Section y), assigned a value of assignments (if appropriate), and guidelines on how
future assignments are to TBD1 from the DHCP Option space
[to be made.

Once a registry has been created, IANA records assignments that have
been made. removed upon publication:
http://www.iana.org/assignments/bootp-dhcp-parameters]
[RFC2132] [RFC2939]:
Data
Tag Name Length Meaning
---- ---- ------ -------
TBD1 FooBar N FooBar server

The following labels describe the status of FooBar option also defines an individual
(or range) of assignments:

Private Use: Private use only (not assigned), as described in
Section 4.1.1.

Experimental: Available 8-bit FooType field, for general experimental use as described
in [RFC3692]. which
IANA does not record specific assignments for
any particular use.

Unassigned: Not currently assigned, and available for assignment
via documented procedures. While it's generally clear that
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 create and not available for assignment.
Reserved maintain a new sub-registry entitled
"FooType values" under the FooBar option. Initial values are held for special uses, such as to extend the namespace when it becomes exhausted. Note that this is
distinctly different from "Unassigned".

4.1. Well-Known IANA Policy Definitions

The following
DHCP FooBar FooType registry are some defined policies, most of which given below; future assignments
are in use
today. These cover a range of typical policies that have been used
to describe the procedure for assigning new values in a namespace.
It is not strictly required that documents use these terms; the
actual requirement is that the instructions to IANA be clear and
unambiguous. However, use of these terms is strongly RECOMMENDED,
because their meanings are widely understood. The terms are fully
explained in the following subsections.

1. Private Use
2. Experimental Use
3. Hierarchical Allocation
4. First Come First Served
5. made through Expert Review
6. Specification Required
7. RFC Required
8. IETF Review
9. Standards Action
10. IESG Approval

It should be noted that it often makes sense to partition a namespace
into multiple categories, with assignments within each category
handled differently. Many protocols now partition namespaces into
two or more parts, with one range reserved for Private or
Experimental Use while other ranges are reserved for globally unique
assignments assigned following some review process. Dividing [BCP26].
Assignments consist of a
namespace into ranges makes it possible to have different policies in
place for different ranges DHCP FooBar FooType name and different use cases.

Similarly, it will often be useful to specify multiple policies in
parallel, with each policy being used under different circumstances. 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 more discussion examples of documents that topic, see Section 4.3.

Examples:
LDAP [RFC4520]
TLS ClientCertificateType Identifiers [RFC5246] (as detailed in
the subsections below)
Pseudowire Edge to Edge Emulation (PWE3) [RFC4446]

4.1.1. Policy: Private Use

For private or local use only, with the type establish registries, consult
[RFC6195], [RFC3575], [RFC3968], and purpose defined by
the local site. No attempt is made to prevent multiple sites from
using the same value in different (and incompatible) ways. [RFC4520].

2.2. Defining an Appropriate Registry Policy

There is
no need for IANA to review such assignments (since IANA does not
record them) and assignments are not generally useful for broad
interoperability. It is the responsibility of the sites making use
of the Private Use range to ensure that no conflicts occur (within
the intended scope of use).

Examples:
Site-specific options in DHCP [RFC2939]
Fibre Channel Port Type Registry [RFC4044]
TLS ClientCertificateType Identifiers 224-255 [RFC5246]

4.1.2. Policy: Experimental Use

Similar several issues to private or local use only, with consider when defining the purpose being to
facilitate experimentation. See [RFC3692] policy for details.

Example:
Experimental Values in IPv4, IPv6, ICMPv4, ICMPv6, UDP, and TCP
Headers [RFC4727]

4.1.3. Policy: Hierarchical Allocation

Delegated managers can assign values provided they have been given
control over that part of the namespace. IANA controls the higher
levels of the namespace according to one
management of the other policies.

Examples:
DNS names
Object Identifiers
IP addresses

4.1.4. Policy: First Come First Served

Assignments are made to anyone on a first come, first served basis.
There is no substantive review of registry.

If the request, other than to ensure
that it registry's namespace is well-formed and doesn't duplicate an existing assignment.
However, requests must include a minimal amount of clerical
information, such as a point of contact (including an email address)
and a brief description of how the value limited, assignments will be used. Additional
information specific to the type of value requested may also need to be provided, as defined by the namespace. For numbers, the exact
value is generally assigned by IANA; with names, specific text
strings can usually be requested.

Examples:
SASL mechanism names [RFC4422]
LDAP Protocol Mechanisms and LDAP Syntax [RFC4520]

4.1.5. Policy: Expert Review

(Sometimes also called "Designated Expert" in earlier editions of
this document.) Review and approval by a designated expert is
required. The required documentation and review criteria for use by
the designated expert should be provided when defining the registry.
For example, see Sections 6 and 7.2 in [RFC3748].

Even when possible, a sense of whether many registrations are expected
over time, or if the registry is expected to be updated infrequently
or in exceptional circumstances only.

Examples:
EAP Method Types [RFC3748]
HTTP Digest AKA algorithm versions [RFC4169]
URI schemes [RFC4395]
GEOPRIV Location Types [RFC4589]

4.1.6. Policy: Specification Required

Review and approval by a Designated Expert is required, (as in
Section 4.1.5) and the values and their meanings must be documented
in a permanent and readily available public specification, in
sufficient detail so that interoperability between independent
implementations space is possible. The Designated Expert will review the
public specification and evaluate whether essentially unlimited, however, it is sufficiently clear usually
desirable to
allow interoperable implementations. The intention behind "permanent
and readily available" is that have at least a document can reasonably be expected minimal review prior to be findable and retrievable long after IANA assignment of the
requested value. Publication of an RFC is an ideal means of
achieving this requirement, but Specification Required is intended to
also cover in
order to:

o prevent the case hoarding of a document published outside or unnecessary wasting of the RFC path. values. For RFC publication, the normal RFC review process is expected to
provide the necessary review for interoperability, though
example, if the
designated expert space consists of text strings, it may be a particularly well-qualified person to
perform such a review.

When specifying this policy, just use the term "Specification
Required". Some specifications have chosen to refer
desirable to it as "Expert
Review with Specification Required", and that only causes confusion.

Examples:
Diffserv-aware TE Bandwidth Constraints Model Identifiers
[RFC4124]
TLS ClientCertificateType Identifiers 64-223 [RFC5246]
ROHC Profile Identifiers [RFC5795]

4.1.7. Policy: RFC Required

RFC publication suffices, as an IETF submission or in any other
stream (currently an RFC Editor Independent Submission [RFC5742] or
an RFC in the IRTF or IAB Stream). Unless otherwise specified, any
type of RFC is sufficient (currently Standards Track, BCP,
Informational, Experimental, Historic).

4.1.8. Policy: IETF Review

(Formerly called "IETF Consensus" in the first edition prevent entities from obtaining large sets of this
document.) New values are assigned only through RFCs in the IETF
Stream -- those that have been shepherded through the IESG as AD-
Sponsored or IETF working group Documents [RFC2026] [RFC5378]. The
intention is strings
that the document and proposed assignment will be
reviewed by the IESG and appropriate IETF working groups (or experts,
if suitable working groups no longer exist) correspond to ensure that the
proposed assignment will not negatively impact interoperability or
otherwise extend IETF protocols in an inappropriate or damaging
manner.

To ensure adequate community review, such documents are shepherded
through the IESG as AD-sponsored or working group documents with an
IETF Last Call.

Examples:
IPSECKEY Algorithm Types [RFC4025]
Accounting-Auth-Method AVP values in DIAMETER [RFC4005]
TLS Extension Types [RFC5246]

4.1.9. Policy: Standards Action

Values are assigned only desirable names (existing company names, for Standards Track RFCs approved by the
IESG.

Examples:
BGP message types [RFC4271]
Mobile Node Identifier option types [RFC4283]
TLS ClientCertificateType Identifiers 0-63 [RFC5246]
DCCP Packet Types [RFC4340]

4.1.10. Policy: IESG Approval

New assignments may be approved by the IESG. Although there is no
requirement
example).

o provide a sanity check that the request be documented in an RFC, the IESG has
discretion to request documents or other supporting materials on a
case-by-case basis.

IESG Approval actually makes sense and
is not intended to be used often or as a "common case";
indeed, it necessary. Experience has seldom been used in practice during the period RFC
2434 was in effect. Rather, it shown that some level of minimal
review from a subject matter expert is intended useful to be available in
conjunction with other policies as a fall-back mechanism prevent
assignments in the case cases where one of the other allowable approval mechanisms cannot be
employed in a timely fashion or for some other compelling reason.
IESG Approval request is malformed or not intended to circumvent the public review
processes implied by other policies that could have been employed
actually needed (for example, an existing assignment for
a particular assignment. IESG Approval would be appropriate,
however, in cases where expediency an
essentially equivalent service already exists).

Perhaps most importantly, unreviewed extensions can impact
interoperability and security. See [RFC6709].

When the namespace is desired essentially unlimited and there is strong
consensus (such as from a working group) for making the assignment.

The following guidelines are suggested for no
potential interoperability or security issues, assigned numbers can
usually be given out to anyone without any evaluation under IESG
Approval:

o The IESG subjective review. In
such cases, IANA can (and should) reject a request if another path for
registration is available make assignments directly, provided that IANA is more appropriate
given detailed instructions on what types of requests it should
grant, and there it is no
compelling reason not able to use that path.

o Before approving a request, the community should be consulted, via
a "call for comments" that provides as much information as do so without exercising subjective
judgement.

When this is
reasonably possible about the request.

Examples:
IPv4 Multicast address assignments [RFC5771]
IPv4 IGMP Type and Code values [RFC3228]
Mobile IPv6 Mobility Header Type and Option values [RFC6275]

4.2. Best Practice for Selecting an Appropriate Policy

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 the case, some level of those policies to apply, review is required.
However, it's important to
get the right balance of adequate review and ease of
registration. In many cases, those needing to register items 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.
We Registration must not make registration policies and procedures be unnecessarily
difficult to navigate,
difficult, 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
(e.g., for limited resources such as bits in a byte or numbers within a
relatively small range, byte, or for items for
which unsupported values can be damaging to protocol operation), in
many cases having items
registered what's in use represented in the registry is more important than putting restrictions on the
registration. A pattern of denial through overly
important. Overly strict review
criteria, or because of criteria and excessive cost in (in time
and effort to get
through the process, discourages effort) discourage people from even attempting to
register their items. And failure make a
registration. If a registry fails to have in-use items registered
adversely affects reflect the protocols protocol elements
actually in use use, it can adversely affect deployment of protocols on
the Internet. Internet, and the registry itself is devalued.

In particular, because policies 7 through 9 require when a registry policy that requires involvement of
working groups,
Working Groups, directorates, and/or communities of former working-
group participants or other bodies 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 Working
Group in the first place, with
its selection of a Standards Action policy for by placing the registry. bar that high.

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.

Therefore, Working groups 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
value from the namespace.

Note: When a designated expert is used, documents MUST NOT name
the designated expert in the document itself; instead, any
suggested names should be relayed to the appropriate Area
Director at the time the document is sent to the IESG for
approval. This is usually done in the document shepherd writeup.

If the request should also be reviewed on a specific public
mailing list (such as the media-types@iana.org for media types),
that mailing address should be specified. Note, however, that
when mailing lists are specified, the requirement for a
designated expert MUST also be specified (see Section 3).

If IANA is expected to make assignments without requiring an
outside review, sufficient guidance MUST be provided so that the
requests can be evaluated with minimal subjectivity.

4. The size, format, and syntax of registry entries. When creating
a new name/number space, authors must describe any technical
requirements on registry (and sub-registry) values (valid ranges
for integers, length limitations on strings, etc.) as well as the
exact format in which registry values should be displayed. For
number 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.). Authors should also clearly specify what fields to record
in the registry.

5. Initial assignments and reservations. Clear instructions should
be provided to identify any initial assignments or registrations.
In addition, any ranges that are to be reserved for "Private
Use", "Reserved", "Unassigned", etc. should be clearly indicated.

When specifying the process for making future assignments, it is
quite acceptable to pick one (or more) look for specific
justification for policies that require significant community
involvement (Specification Required, in terms of the example well-known
policies).

2.2.1. Using the Well-Known Registration Policies

This document defines a number of registration policies listed in Section 4.1 4.
Because they benefit from both community experience and refer to it by name. Indeed, this wide
understanding, their use is the
preferred mechanism in those cases where the sample policies provide
the desired level of review. encouraged when appropriate.

It is also acceptable to cite one of the above well-known policies and
include additional guidelines for what kind of 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:

---------------------------------------------------------------
This document defines

The well-known policies from "First Come First Served" to "Standards
Action" specify a new DHCP option, entitled "FooBar" (see
Section y), assigned 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 value 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.

Examples of TBD1 from situations that might merit RFC Required, IETF Review, or
Standards Action include the DHCP Option space
[to following:

o When a resource is limited, 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 When thorough community review is necessary to avoid extending or
modifying the protocol in ways that could be removed upon publication:
http://www.iana.org/assignments/bootp-dhcp-parameters]
[RFC2132] [RFC2939]:
Data
Tag Name Length Meaning
---- ---- ------ -------
TBD1 FooBar N FooBar server 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.

The FooBar option also defines an 8-bit FooType field, description in Section 4.10 of "IESG Approval" suggests that the
IESG "can (and should) reject a request if another path for which
IANA
registration is available that is more appropriate and there is no
compelling reason not to create 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 maintain a new sub-registry entitled
"FooType values" under the FooBar option. Initial values strict policy is
the right one.

Accordingly, document developers need to anticipate this and document
their considerations for selecting the
DHCP FooBar FooType registry are given below; future assignments
are specified policy (ideally, in
the document itself; failing that, in the shepherd writeup).
Likewise, 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 made through Expert Review [BCP26].
Assignments consist
reviewed in light of experience since the policies were set.

Note that the well-known policies are not exclusive; there are
situations where a DHCP FooBar FooType name and its
associated value.

2.2.2. Using Multiple Policies in Combination

In some situations, it is necessary to define multiple registration
policies. For examples of documents that provide detailed guidance example, registrations through the normal IETF process
might use one policy, while registrations from outside the process
would have a different policy applied.

Thus, a particular registry might want to IANA on use a policy such as "RFC
Required" or "IETF Review" sometimes, with a designated expert
checking a "Specification Required" policy at other times.

The alternative to using a combination requires either that all
requests come through RFCs or that requests in RFCs go through review
by the issue of assigning numbers, consult [RFC6195], [RFC3575],
[RFC3968], designated expert, even though they already have IETF review
and [RFC4520].

4.5. Updating consensus.

This can be documented in the IANA Guidelines for Considerations section when the
registry is created:

Such combinations will commonly use one of {Standards Action, IETF
Review, RFC Required} in combination with one of {Specification
Required, Expert Review}.

2.3. Revising Existing Registries

Updating the registration process for an already existing (previously
created) namespace (whether created explicitly or implicitly) follows
a process similar to that used when creating a new namespace. That
is, a document is produced that makes reference to the existing
namespace and then provides detailed guidelines for handling
assignments in each individual namespace. Such documents are
normally processed as Best Current Practices (BCPs) [RFC2026].

Example documents that updated the guidelines for managing (then)
pre-existing registries include: [RFC6195], [RFC3228], and [RFC3575].

3. Registering New Values in an Existing Registry

5.1. What to Put in Documents When Registering Values

3.1. Documentation Requirements for Registrations

Often, documents request an assignment from an already existing
namespace (one created by a previously published document). In such
cases:

o Documents

Such documents should clearly identify the namespace in which each
value is to be registered. If the registration goes into a sub-
registry, the author should clearly describe where the assignment or
registration should go. It is helpful to use Use the *exact* exact namespace name as listed on
the IANA web page (please look it up,
and don't guess), page, and cite the RFC where the namespace is defined.

Note 1:

There is no need to mention what the assignment policy for new
assignments is, as that should be clear from the references.

Note 2:

When referring to an existing registry, providing a URL to precisely
identify the registry is helpful. Such URLs, however, should usually
be removed from the RFC prior to final publication, since IANA URLs
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.

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]

o 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.

5.2.

3.2. Updating Existing Registrations

Registrations are a request to assign a new value, including the
related information needed to evaluate and document the request.

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,
etc. tags
typically include more information than just the registered value itself. Example information can include
itself, and may need things such as point-of-contact information,
security issues, pointers to updates, or literature
references, etc. references
updated.

In such cases, the document defining the namespace must clearly state
who is responsible for maintaining and updating a registration. In different cases,
Depending on the registry, it may be appropriate to specify one or
more of the following: of:

o Let the author Letting registrants and/or nominated change controllers update the registration,
their own registrations, subject to the same constraints and
review as with new registrations.

o Allow some mechanism to attach Allowing attachment of comments to the registration, for registration. This can be
useful in cases where others have significant objections to claims in a
registration, but the author does not agree to change the
registration.

o Designate 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.

5.3.

3.3. Overriding Registration Procedures

Since RFC 2434 was published, experience

Experience has shown that the documented IANA considerations for
individual protocols do not always adequately cover the reality after the protocol is deployed. For
example, many older routing protocols do of
registry operation, or are not have documented,
detailed IANA considerations. 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
obtain code points from IANA perform a registration 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, cases, the IESG is granted
authority to override registration procedures and approve assignments in
such cases.
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. Instead, the intention Rather, it is to permit assignments in individual specific
cases where it is obvious that the assignment should just be made,
but updating the IANA process just 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
today. These cover a range of typical policies that have been used
to describe the procedure for assigning new values in a namespace.
It is not strictly required that documents use these terms; the
actual requirement is that the instructions to IANA be clear and
unambiguous. However, use of these terms is strongly RECOMMENDED,
because their meanings are widely understood. The terms are fully
explained in the following subsections.

1. Private Use
2. Experimental Use
3. Hierarchical Allocation
4. First Come First Served
5. Expert Review
6. Specification Required
7. RFC Required
8. IETF Review
9. Standards Action
10. IESG Approval

It should be noted that it often makes sense to partition a namespace
into multiple categories, with assignments within each category
handled differently. Many protocols now partition namespaces into
two or more parts, with one range reserved for Private or
Experimental Use while other ranges are reserved for globally unique
assignments assigned following some review process. Dividing a
namespace into ranges makes it possible to have different policies in
place for different ranges and different use cases.

Similarly, it will often be useful to specify multiple policies in
parallel, with each policy being used under different circumstances.
For more discussion of that topic, see Section 2.2.2.

Examples:

LDAP [RFC4520]
TLS ClientCertificateType Identifiers [RFC5246] (as detailed in
the subsections below)
Pseudowire Edge to Edge Emulation (PWE3) [RFC4446]

4.1. Private Use
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
using the same value in different (and incompatible) ways. There is
no need for IANA to review such assignments (since IANA does not
record them) and assignments are not generally useful for broad
interoperability. It is the responsibility of the sites making use
of the Private Use range to ensure that no conflicts occur (within
the intended scope of use).

Examples:

Site-specific options in DHCP [RFC2939]
Fibre Channel Port Type Registry [RFC4044]
TLS ClientCertificateType Identifiers 224-255 [RFC5246]

4.2. Experimental Use

Similar to private or local use only, with the purpose being to
facilitate experimentation. See [RFC3692] for details.

Example:

Experimental Values in IPv4, IPv6, ICMPv4, ICMPv6, UDP, and TCP
Headers [RFC4727]

4.3. Hierarchical Allocation

Delegated managers can assign values provided they have been given
control over that part of the namespace. IANA controls the higher
levels of the namespace according to one of the other policies.

Examples:

DNS names
Object Identifiers
IP addresses

4.4. First Come First Served

Assignments are made to anyone on a particular code point first come, first served basis.
There is no substantive review of the request, other than to ensure
that it is viewed well-formed and doesn't duplicate an existing assignment.
However, requests must include a minimal amount of clerical
information, such as too heavy a burden.

In general, point of contact (including an email address)
and a brief description of how the IETF would like value will be used. Additional
information specific to the type of value requested may also need to
be provided, as defined by the namespace. For numbers, the exact
value is generally assigned by IANA; with names, specific text
strings can usually be requested.

Examples:

SASL mechanism names [RFC4422]
LDAP Protocol Mechanisms and LDAP Syntax [RFC4520]

4.5. Expert Review

It is particularly important, when using a designated expert, to give
clear guidance to the expert, laying out criteria for performing an
evaluation and reasons for rejecting a request. When specifying a
policy that involves a designated expert, the IANA registration
procedures Considerations
SHOULD contain such guidance. It is also a good idea to include,
when possible, a sense of whether many registrations are expected
over time, or if the registry is expected to be updated infrequently
or in exceptional circumstances only.

Examples:

EAP Method Types [RFC3748]
HTTP Digest AKA algorithm versions [RFC4169]
URI schemes [RFC4395]
GEOPRIV Location Types [RFC4589]

4.6. Specification Required

Review and approval by a Designated Expert is required, (as in
Section 4.5) and the values and their meanings must be documented in
a permanent and readily available public specification, in sufficient
detail so that interoperability between independent implementations
is possible. The Designated Expert will review the public
specification and evaluate whether it is sufficiently clear to allow
interoperable implementations. The intention behind "permanent and
readily available" is that a document can reasonably be expected to
be findable and retrievable long after IANA assignment of the
requested value. Publication of an RFC is an ideal means of
achieving this requirement, but Specification Required is intended to
also cover the case of a document published outside of the RFC path.
For RFC publication, the normal RFC review process is expected to
provide the necessary review for interoperability, though the
designated expert may be a namespace revised particularly well-qualified person to
perform such a review.

When specifying this policy, just use the term "Specification
Required". Some specifications have chosen to refer to it as "Expert
Review with Specification Required", and that only causes confusion.

Examples:

Diffserv-aware TE Bandwidth Constraints Model Identifiers
[RFC4124]
TLS ClientCertificateType Identifiers 64-223 [RFC5246]
ROHC Profile Identifiers [RFC5795]

4.7. RFC Required

4.8. IETF Review

(Formerly called "IETF Consensus" in the first edition of this
document.) New values are assigned only through RFCs in the IETF standards
process, but
Stream -- those that have been shepherded through the IESG as AD-
Sponsored or IETF working group Documents [RFC2026] [RFC5378]. The
intention is that the document and proposed assignment will be
reviewed by the IESG and appropriate IETF working groups (or experts,
if suitable working groups no longer exist) to ensure that the
proposed assignment will not at negatively impact interoperability or
otherwise extend IETF protocols in an inappropriate or damaging
manner.

To ensure adequate community review, such documents are shepherded
through the cost of unreasonable delay IESG as AD-sponsored or working group documents with an
IETF Last Call.

Examples:

IPSECKEY Algorithm Types [RFC4025]
Accounting-Auth-Method AVP values in DIAMETER [RFC4005]
TLS Extension Types [RFC5246]

4.9. Standards Action

Values are assigned only for needed
assignments. If Standards Track RFCs approved by the
IESG.

Examples:

BGP message types [RFC4271]
Mobile Node Identifier option types [RFC4283]
TLS ClientCertificateType Identifiers 0-63 [RFC5246]
DCCP Packet Types [RFC4340]

4.10. IESG Approval

New assignments may be approved by the IESG. Although there is no
requirement that the request be documented in an RFC, the IESG has had
discretion to take request documents or other supporting materials on a
case-by-case basis.

IESG Approval is not intended to be used often or as a "common case";
indeed, it has seldom been used in practice during the action period RFC
2434 was in this section, effect. Rather, it is intended to be available in
conjunction with other policies as a fall-back mechanism in the case
where one of the other allowable approval mechanisms cannot be
employed in a timely fashion or for some other compelling reason.
IESG Approval is not intended to circumvent the public review
processes implied by other policies that could have been employed for
a particular assignment. IESG Approval would be appropriate,
however, in cases where expediency is desired and there is strong indicator
consensus (such as from a working group) for making the assignment.

The following guidelines are suggested for any evaluation under IESG
Approval:

o 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.

o Before approving a request, the community should be consulted, via
a "call for comments" that provides as much information as is
reasonably possible about the request.

Examples:

IPv4 Multicast address assignments [RFC5771]
IPv4 IGMP Type and Code values [RFC3228]
Mobile IPv6 Mobility Header Type and Option values [RFC6275]

5. Designated Experts

5.1. The Motivation for Designated Experts

IANA does not define registry policy itself; rather, it carries out
policies that have been defined by others and published in RFCs. As
part of that process, review of proposed registrations is often
appropriate.

A common way to ensure such review is for a proposed registration procedures to
be published as an RFC, as this ensures that the specification is
publicly and permanently available. It is particularly important if
any potential interoperability issues might arise. For 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
register a protocol element is excessive.

However, it is generally still useful (and sometimes necessary) to
discuss proposed registrations within the community, on a mailing
list. Such a mailing list provides opportunity for public review
prior to assignment, and allows for a consultative process when
registrants want help in understanding what a proper registration
should contain.

While discussion on a mailing list can provide valuable technical
feedback, opinions may vary and discussions may continue for some
time without clear resolution. In addition, IANA cannot participate
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 updated, possibly 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
experts is for the IETF to provide IANA with a subject matter expert
to whom the evaluation process can be delegated. IANA forwards
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
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

The designated expert is responsible for initiating and coordinating
the appropriate review of an assignment request. The review may be
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 specific examples.

Designated experts are expected to be able to defend their decisions
to the IETF community, and the evaluation process is not intended to
be secretive or bestow unquestioned power on the expert. Experts are
expected to apply applicable documented review or vetting procedures,
or in parallel the absence of documented criteria, follow generally accepted
norms such as those in Section 5.3.

Section 3.2 discusses disputes and appeals in more detail.

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.

For some registries, it has proven useful to have multiple designated
experts. Sometimes those experts work together in evaluating a
request, while in other cases additional experts serve as backups.
In cases of disagreement among those experts, it is the
responsibility of those experts to make a single clear recommendation
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
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.

Since the designated experts are appointed by the IESG, they may be
removed by the IESG.

5.3. Designated Expert Reviews

In the years since RFC 2434 was published and has been put to use,
experience has led to the following observations:

o A designated expert must respond in a timely fashion, normally
within a week for simple requests to a few weeks for more complex
ones. Unreasonable delays can cause significant problems for
those needing assignments, such as when products need code points
to ship. This is not to say that all reviews can be completed
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
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.

o The designated expert is not required to personally bear the
burden of evaluating and deciding all requests, but acts as a
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
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
should be prudently managed, or when a request for a large number
of code points is made, when a single code point is the norm.

o Documentation is not of sufficient clarity to evaluate or ensure
interoperability.

o The code point is needed for a protocol extension, but the
extension is not consistent with ongoing the documented (or generally
understood) architecture of the base protocol being extended, and
would be harmful to the protocol work. if widely deployed. It is not
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.

o The extension would conflict with one under active development by
the IETF, and having both would harm rather than foster
interoperability.

When a designated expert is used, documents MUST NOT name the
designated expert in the document itself; instead, any suggested
names should be relayed to the appropriate Area Director at the time
the document is sent to the IESG for approval. This is usually done
in the document shepherd writeup.

If the request should also be reviewed on a specific public mailing
list, its address should be specified.

5.4. Expert Reviews and the Document Lifecycle

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.

It is possible, through carelessness, accident, inattentiveness, or
even willful disregard, that changes might be made after the
designated expert's review and approval that would, if the document
were re-reviewed, cause the expert not to approve the registration.
It is up to the IESG, with the token held by the responsible Area
Director, to be alert to such situations and to recognize that such
changes need to be checked.

6. Well-Known Registration Status Terminology

The following labels describe the status of an individual (or range)
of assignments:

Private Use: Private use only (not assigned), as described in
Section 4.1.

Experimental: Available for general experimental use as described
in [RFC3692]. IANA does not record specific assignments for
any particular use.

Reserved: Not assigned and not available for assignment. Reserved
values are held for special uses, such as to extend the
namespace when it becomes exhausted. Note that this is
distinctly different from "Unassigned".

7. Documentation References in IANA Registries

Usually, registries and registry entries include references to
documentation (RFCs or other documents). The purpose of these
references is to provide pointers for implementors to find details
necessary for implementation, NOT to simply note what document
created the registry or entry. Therefore:

o If a document registers an item that is defined and explained
elsewhere, the registered reference should be to that document,
and not to the document that is merely performing the
registration.

o If the registered item is defined and explained in the current
document, it is important to include sufficient information to
enable implementors to understand the item and to create a proper
implementation.

o If the registered item is explained primarily in a specific
section of the reference document, it is useful to include a
section reference. For example, "[RFC9876], Section 3.2", rather
than just "[RFC9876]".

o For documentation of a new registry, the reference should provide
information about the registry itself, not just a pointer to the
creation of it. Useful information includes the purpose of the
registry, a rationale for its creation, documentation of the
process and policy for new registrations, guidelines for new
registrants or designated experts, and other such related
information.

8. What to Do in "bis" Documents

We often produce a new edition of

On occaison, an RFC, which RFC is issued that obsoletes the a previous edition (we of
the same document. We sometimes call these "bis" documents, such as
when RFC 9876 is updated by draft-ietf-foo-rfc9876bis). draft-ietf-foo-rfc9876bis. When the
original document created registries and/or registered entries, there
is a question of how to handle the IANA Considerations section in the
"bis" document.

If the registrations specify the original document as a reference,
those registrations should be updated to point to the current (not
obsolete) documentation for those items. Usually, that will mean
changing the reference to be the "bis" document.

For example, suppose RFC 9876 registered the "BANANA" flag in the
"Fruit Access Flags" registry, and the documentation for that flag is
in Section 3.2.

The current registry might look, in part, like this:

Name Description Reference
-------- ------------------- ---------
BANANA Flag for bananas [RFC9876], Section 3.2

If draft-ietf-foo-rfc9876bis obsoletes RFC 9876 and, because of some
rearrangement, now documents the flag in Section 4.1.2, the IANA
Considerations of the bis document might contain text such as this:

IANA is asked to change the registration information for the
BANANA flag in the "Fruit Access Flags" registry to the following:

Name Description Reference
-------- ------------------- ---------
BANANA Flag for bananas [[this RFC]], Section 4.2.1

In many cases, if there are a number of registered references to the
original RFC and the document organization has not changed the
registered section numbering much, it may simply be reasonable to do
this:

Because this document obsoletes RFC 9876, IANA is asked to change
all registration information that references [RFC9876] to instead
reference [[this RFC]].

If information for registered items has been or is being moved to
other documents, then, of course, the registration information should
be changed to point to those other documents. In no case is it
reasonable to leave documentation pointers to the obsoleted document
for any registries or registered items that are still in current use.

9. Miscellaneous Issues

8.1.

9.1. When There Are No IANA Actions
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
that it is not always immediately obvious whether a document has no
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
that the author has consciously made such a determination), such
documents should include an IANA Considerations section that states:

This document has no IANA actions.

This statement, or an equivalent, must only be inserted after the
working group or individual submitter has carefully verified it to be
true. Using such wording as a matter of "boilerplate" or without
careful consideration can lead to incomplete or incorrect IANA
actions being performed.

If a specification makes use of values from a namespace that is not
managed by IANA, it may be useful to note this fact, with wording
such as this:

The values of the Foobar parameter are assigned by the Barfoo
registry on behalf of the Rabfoo Forum. Therefore, this document
has no IANA actions.

In some cases, the absence of IANA-assigned values may be considered
valuable information for future readers; in other cases, it may be
considered of no value once the document has been approved, and may
be removed before archival publication. This choice should be made
clear in the draft, for example, by including a sentence such as

[RFC Editor: please remove this section prior to publication.]

[RFC Editor: please do not remove this section.]

8.2.

9.2. Namespaces Lacking Documented Guidance

For all existing RFCs that either explicitly or implicitly rely on
IANA to evaluate assignments without specifying a precise evaluation
policy, IANA (in consultation with the IESG) will continue to decide
what policy is appropriate. Changes to existing policies can always
be initiated through the normal IETF consensus process.

All future RFCs that either explicitly or implicitly rely on IANA to
register or otherwise manage namespace assignments MUST provide
guidelines for managing the namespace.

8.3.

9.3. After-the-Fact Registrations
Occasionally, IANA becomes aware that an unassigned value from a
managed namespace is in use on the Internet or that an assigned value
is being used for a different purpose than originally registered.
IANA will not condone such misuse; procedures of the type described
in this document MUST be applied to such cases. In the absence of
specifications to the contrary, values may only be reassigned for a
different purpose with the consent of the original assignee (when
possible) and with due consideration of the impact of such a
reassignment. In cases of likely controversy, consultation with the
IESG is advised.

8.4.

9.4. Reclaiming Assigned Values

Reclaiming previously assigned values for reuse is tricky, because
doing so can lead to interoperability problems with deployed systems
still using the assigned values. Moreover, it can be extremely
difficult to determine the extent of deployment of systems making use
of a particular value. However, in cases where the namespace is
running out of unassigned values and additional ones are needed, it
may be desirable to attempt to reclaim unused values. When
reclaiming unused values, the following (at a minimum) should be
considered:

o Attempts should be made to contact the original party to which a
value is assigned, to determine if the value was ever used, and if
so, the extent of deployment. (In some cases, products were never
shipped or have long ceased being used. In other cases, it may be
known that a value was never actually used at all.)

o Reassignments should not normally be made without the concurrence
of the original requester. Reclamation under such conditions
should only take place where there is strong evidence that a value
is not widely used, and the need to reclaim the value outweighs
the cost of a hostile reclamation. In any case, IESG Approval is
needed in this case.

o It may be appropriate to write up the proposed action and solicit
comments from relevant user communities. In some cases, it may be
appropriate to write an RFC that goes through a formal IETF
process (including IETF Last Call) as was done when DHCP reclaimed
some of its "Private Use" options [RFC3942].

8.5.

9.5. Contact Person vs Assignee or Owner

Many registries include designation of a technical or administrative
contact associated with each entry. Often, this is recorded as
contact information for an individual. It is unclear, though, what
role the individual has with respect to the registration: is this
item registered on behalf of the individual, the company the
individual worked for, or perhaps another organization the individual
was acting for?
This matters because some time later, when the individual has changed
jobs or roles, and perhaps can no longer be contacted, someone might
want to update the registration. IANA has no way to know what
company, organization, or individual should be allowed to take the
registration over. For registrations rooted in RFCs, the stream
owner (such as the IESG or the IAB) can make an overriding decision.
But in other cases, there is no recourse.

Registries can include, in addition to a "Contact" field, an
"Assignee" or "Owner" field that can be used to address this
situation, giving IANA clear guidance as to the actual owner of the
registration. Alternatively, organizations can put an organizational
role into the "Contact" field in order to make their ownership clear.

8.6.

9.6. Closing or Obsoleting a Registry

[[anchor2: This

[[This section needs to be resolved before publication.]]

8.7.

9.7. BCP 78/79 Issues in Registries

[[anchor3: This

[[This section needs to be resolved before publication.]]

9. publication, but I'm not
sure anything's needed here after all. ]]

10. Appeals

Appeals of registration decisions made by IANA can be made using the
normal IETF appeals process as described in Section 6.5 of [RFC2026].
Specifically, appeals should be directed to the IESG, followed (if
necessary) by an appeal to the IAB, etc.

10.

11. Mailing Lists

All IETF mailing lists associated with evaluating or discussing
assignment requests as described in this document are subject to
whatever rules of conduct and methods of list management are
currently defined by Best Current Practices or by IESG decision.

11.

12. Security Considerations

Information that creates or updates a registration needs to be
authenticated and authorized. IANA updates registries according to
instructions in published RFCs and from the IESG. It also may accept
clarifications from document authors, relevant working group chairs,
Designated Experts, and mail list participants, too.

Information concerning possible security vulnerabilities of a
protocol may change over time. Likewise, security vulnerabilities
related to how an assigned number is used may change as well. As new
vulnerabilities are discovered, information about such
vulnerabilities may need to be attached to existing registrations, so
that users are not misled as to the true security issues surrounding
the use of a registered number.

An analysis of security issues is generally required for all
protocols that make use of parameters (data types, operation codes,
keywords, etc.) used in IETF protocols or registered by IANA. Such
security considerations are usually included in the protocol document
[RFC3552]. It is the responsibility of the IANA considerations
associated with a particular registry to specify what (if any)
security considerations must be provided when assigning new values,
and the process for reviewing such claims.

12.

13. To-Do List; resolve and remove before requesting publication

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

12.1. 2012:

14.1. 2013: Changes in This Document Relative to RFC 5226

Significant additions:

o Added Section 3.4, 5.4, Expert Reviews and the Document Lifecycle

o Moved well-known policies into a separate section for each,
subsections of Section 4.1. 4.

o Added Section 4.2, 2.2, Best Practice for Selecting an Appropriate
Policy.

o Added Section 4.3, 2.2.2, Using Multiple Policies in Combination.

o Added Section 6, 7, Documentation References in IANA Registries

o Added Section 7, 8, What to Do in "bis" Documents

o Added Section 8.5, 9.5, Contact Person vs Assignee or Owner

o Added Section 8.6, 9.6, Closing or Obsoleting a Registry

o Added Section 8.7, 9.7, BCP 78/79 Issues in Registries

Clarifications and such:

o Some reorganization -- moved text around for clarity and easier
reading.

o Made clarifications about identification of IANA registries and
use of URLs for them.

o Clarified the distinction between "Unassigned" and "Reserved".

o Made some clarifications in "Expert Review" about instructions to
the designated expert.

o Made some clarifications in "Specification Required" about how to
declare this policy.

o Assorted minor clarifications and editorial changes throughout.

12.2.

14.2. 2008: Changes in RFC 5226 Relative to RFC 2434

Changes include:

o Major reordering of text to expand descriptions and to better
group topics such as "updating registries" vs. "creating new
registries", in order to make it easier for authors to find the
text most applicable to their needs.

o Numerous editorial changes to improve readability.

o Changed the term "IETF Consensus" to "IETF Review" and added more
clarifications. History has shown that people see the words "IETF
Consensus" (without consulting the actual definition) and are
quick to make incorrect assumptions about what the term means in
the context of IANA Considerations.

o Added "RFC Required" to list of defined policies.

o Much more explicit directions and examples of "what to put in
RFCs".

o "Specification Required" now implies use of a Designated Expert to
evaluate specs for sufficient clarity.

o Significantly changed the wording in the Designated Experts
section. Main purpose is to make clear that Expert Reviewers are
accountable to the community, and to provide some guidance for
review criteria in the default case.

o Changed wording to remove any special appeals path. The normal
RFC 2026 appeals path is used.

o Added a section about reclaiming unused value.

o Added a section on after-the-fact registrations.

o Added a section indicating that mailing lists used to evaluate
possible assignments (such as by a Designated Expert) are subject
to normal IETF rules.

13.

15. Acknowledgments

13.1.

15.1. Acknowledgments for This Document (2012) (2013)
Thomas Narten and Harald Tveit Alvestrand edited the two earlier
editions of this document (RFCs 2434 and 5226), and Thomas continues
his role in this third edition. Most Much of the text from RFC 5226
remains in this edition.

13.2.

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:

This document has benefited from specific feedback from Jari Arkko,
Marcelo Bagnulo Braun, Brian Carpenter, Michelle Cotton, Spencer
Dawkins, Barbara Denny, Miguel Garcia, Paul Hoffman, Russ Housley,
John Klensin, Allison Mankin, Blake Ramsdell, Mark Townsley, Magnus
Westerlund, and Bert Wijnen.

13.3.

15.3. Acknowledgments from the first edition (1998)

The original acknowledgments section in RFC 2434 was:

Jon Postel and Joyce Reynolds provided a detailed explanation on what
IANA needs in order to manage assignments efficiently, and patiently
provided comments on multiple versions of this document. Brian
Carpenter provided helpful comments on earlier versions of the
document. One paragraph in the Security Considerations section was
borrowed from [RFC4288].

14.

16. References

14.1.

16.1. Normative References

[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119, March 1997.

14.2.

16.2. Informative References

[RFC0791] Postel, J., "Internet Protocol", STD 5, RFC 791, September
1981.

[RFC2026] Bradner, S., "The Internet Standards Process -- Revision
3", BCP 9, RFC 2026, October 1996.

[RFC2132] Alexander, S. and R. Droms, "DHCP Options and BOOTP Vendor
Extensions", RFC 2132, March 1997.

[RFC2860] Carpenter, B., Baker, F., F. and M. Roberts, "Memorandum of
Understanding Concerning the Technical Work of the
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
of New DHCP Options and Message Types", BCP 43, RFC 2939,
September 2000.

[RFC3228] Fenner, B., "IANA Considerations for IPv4 Internet Group
Management Protocol (IGMP)", BCP 57, RFC 3228, February
2002.

[RFC3232] Reynolds, J., "Assigned Numbers: RFC 1700 is Replaced by
an On-line Database", RFC 3232, January 2002.

[RFC3552] Rescorla, E. and B. Korver, "Guidelines for Writing RFC
Text on Security Considerations", BCP 72, RFC 3552, July
2003.

[RFC3575] Aboba, B., "IANA Considerations for RADIUS (Remote
Authentication Dial In User Service)", RFC 3575, July
2003.

[RFC3692] Narten, T., "Assigning Experimental and Testing Numbers
Considered Useful", BCP 82, RFC 3692, January 2004.

[RFC3748] Aboba, B., Blunk, L., Vollbrecht, J., Carlson, J., J. and H.
Levkowetz, "Extensible Authentication Protocol (EAP)", RFC
3748, June 2004.

[RFC3942] Volz, B., "Reclassifying Dynamic Host Configuration
Protocol version 4 (DHCPv4) Options", RFC 3942, November
2004.

[RFC3968] Camarillo, G., "The Internet Assigned Number Authority
(IANA) Header Field Parameter Registry for the Session
Initiation Protocol (SIP)", BCP 98, RFC 3968, December
2004.

[RFC4005] Calhoun, P., Zorn, G., Spence, D., D. and D. Mitton, "Diameter
Network Access Server Application", RFC 4005, August 2005.

[RFC4025] Richardson, M., "A Method for Storing IPsec Keying
Material in DNS", RFC 4025, March 2005.

[RFC4044] McCloghrie, K., "Fibre Channel Management MIB", RFC 4044,
May 2005.

[RFC4124] Le Faucheur, F., "Protocol Extensions for Support of
Diffserv-aware MPLS Traffic Engineering", RFC 4124, June
2005.

[RFC4169] Torvinen, V., Arkko, J., J. and M. Naslund, "Hypertext
Transfer Protocol (HTTP) Digest Authentication Using
Authentication and Key Agreement (AKA) Version-2", RFC
4169, November 2005.

[RFC4271] Rekhter, Y., Li, T., T. and S. Hares, "A Border Gateway
Protocol 4 (BGP-4)", RFC 4271, January 2006.

[RFC4283] Patel, A., Leung, K., Khalil, M., Akhtar, H., H. and K.
Chowdhury, "Mobile Node Identifier Option for Mobile IPv6
(MIPv6)", RFC 4283, November 2005.

[RFC4288] Freed, N. and J. Klensin, "Media Type Specifications and
Registration Procedures", BCP 13, RFC 4288, December 2005.

[RFC4301] Kent, S. and K. Seo, "Security Architecture for the
Internet Protocol", RFC 4301, December 2005.

[RFC4340] Kohler, E., Handley, M., M. and S. Floyd, "Datagram Congestion
Control Protocol (DCCP)", RFC 4340, March 2006.

[RFC4395] Hansen, T., Hardie, T., T. and L. Masinter, "Guidelines and
Registration Procedures for New URI Schemes", BCP 35, RFC
4395, February 2006.

[RFC4422] Melnikov, A. and K. Zeilenga, "Simple Authentication and
Security Layer (SASL)", RFC 4422, June 2006.

[RFC4446] Martini, L., "IANA Allocations for Pseudowire Edge to Edge
Emulation (PWE3)", BCP 116, RFC 4446, April 2006.

[RFC4520] Zeilenga, K., "Internet Assigned Numbers Authority (IANA)
Considerations for the Lightweight Directory Access
Protocol (LDAP)", BCP 64, RFC 4520, June 2006.

[RFC4589] Schulzrinne, H. and H. Tschofenig, "Location Types
Registry", RFC 4589, July 2006.

[RFC4727] Fenner, B., "Experimental Values In IPv4, IPv6, ICMPv4,
ICMPv6, UDP, and TCP Headers", RFC 4727, November 2006.

[RFC5246] Dierks, T. and E. Rescorla, "The Transport Layer Security
(TLS) Protocol Version 1.2", RFC 5246, August 2008.

[RFC5378] Bradner, S. and J. Contreras, "Rights Contributors Provide
to the IETF Trust", BCP 78, RFC 5378, November 2008.

[RFC5742] Alvestrand, H. and R. Housley, "IESG Procedures for
Handling of Independent and IRTF Stream Submissions", BCP
92, RFC 5742, December 2009.

[RFC5771] Cotton, M., Vegoda, L., L. and D. Meyer, "IANA Guidelines for
IPv4 Multicast Address Assignments", BCP 51, RFC 5771,
March 2010.

[RFC5795] Sandlund, K., Pelletier, G., G. and L-E. Jonsson, "The RObust
Header Compression (ROHC) Framework", RFC 5795, March
2010.

[RFC6195] Eastlake, D., "Domain Name System (DNS) IANA
Considerations", BCP 42, RFC 6195, March 2011.

[RFC6275] Perkins, C., Johnson, D., D. and J. Arkko, "Mobility Support
in IPv6", RFC 6275, July 2011.

[RFC6709] Carpenter, B., Aboba, B., B. and S. Cheshire, "Design
Considerations for Protocol Extensions", RFC 6709,
September 2012.

Authors' Addresses

Michelle Cotton Cotton, Manager, IANA Services
Internet Corporation for Assigned Names and Numbers Authority (IANA)
4676 Admiralty Way,
12025 Waterfront Drive, Suite 330
Marina del Rey, 300
Los Angeles, CA 90292
USA 90094-2536
US

Phone: +1 310 301 5812
Email: michelle.cotton@icann.org

Barry Leiba
Huawei Technologies

Phone: +1 646 827 0648
Email: barryleiba@computer.org
URI: http://internetmessagingtechnology.org/

Thomas Narten
IBM Corporation
3039 Cornwallis Ave., PO Box 12195 - BRQA/502
Research Triangle Park, NC 27709-2195
USA
US

Phone: +1 919 254 7798
Email: narten@us.ibm.com