tech-invite   World Map     

3GPP     Specs     Glossaries     Architecture     IMS     UICC       IETF     RFCs     Groups     SIP     ABNFs       Search

RFC 8126

BCP 26
Pages: 47
Top     in Index     Prev     Next
in Group Index     Prev in Group     No Next: Highest Number in Group     Group: ~iana

Guidelines for Writing an IANA Considerations Section in RFCs

Part 1 of 3, p. 1 to 15
None       Next Section

Obsoletes:    5226

Top       ToC       Page 1 
Internet Engineering Task Force (IETF)                         M. Cotton
Request for Comments: 8126                                           PTI
BCP: 26                                                         B. Leiba
Obsoletes: 5226                                      Huawei Technologies
Category: Best Current Practice                                T. Narten
ISSN: 2070-1721                                          IBM Corporation
                                                               June 2017

     Guidelines for Writing an IANA Considerations Section in RFCs


   Many protocols make use of points of extensibility that use constants
   to identify various protocol parameters.  To ensure that the values
   in these fields do not have conflicting uses and to promote
   interoperability, their allocations are often coordinated by a
   central record keeper.  For IETF protocols, that role is filled by
   the Internet Assigned Numbers Authority (IANA).

   To make assignments in a given registry prudently, guidance
   describing the conditions under which new values should be assigned,
   as well as when and how modifications to existing values can be made,
   is needed.  This document defines a framework for the documentation
   of these guidelines by specification authors, in order to assure that
   the provided guidance for the IANA Considerations is clear and
   addresses the various issues that are likely in the operation of a

   This is the third edition of this document; it obsoletes RFC 5226.

Status of This Memo

   This memo documents an Internet Best Current Practice.

   This document is a product of the Internet Engineering Task Force
   (IETF).  It represents the consensus of the IETF community.  It has
   received public review and has been approved for publication by the
   Internet Engineering Steering Group (IESG).  Further information on
   BCPs is available in Section 2 of RFC 7841.

   Information about the current status of this document, any errata,
   and how to provide feedback on it may be obtained at

[Page 2] 
Copyright Notice

   Copyright (c) 2017 IETF Trust and the persons identified as the
   document authors.  All rights reserved.

   This document is subject to BCP 78 and the IETF Trust's Legal
   Provisions Relating to IETF Documents
   ( 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  . . . . . . . . . . . . . . . . . . . . . . . .   4
     1.1.  Keep IANA Considerations for IANA . . . . . . . . . . . .   4
     1.2.  For Updated Information . . . . . . . . . . . . . . . . .   5
     1.3.  A Quick Checklist Upfront . . . . . . . . . . . . . . . .   5
   2.  Creating and Revising Registries  . . . . . . . . . . . . . .   7
     2.1.  Organization of Registries  . . . . . . . . . . . . . . .   8
     2.2.  Documentation Requirements for Registries . . . . . . . .   8
     2.3.  Specifying Change Control for a Registry  . . . . . . . .  11
     2.4.  Revising Existing Registries  . . . . . . . . . . . . . .  11
   3.  Registering New Values in an Existing Registry  . . . . . . .  12
     3.1.  Documentation Requirements for Registrations  . . . . . .  12
     3.2.  Updating Existing Registrations . . . . . . . . . . . . .  14
     3.3.  Overriding Registration Procedures  . . . . . . . . . . .  14
     3.4.  Early Allocations . . . . . . . . . . . . . . . . . . . .  15
   4.  Choosing a Registration Policy and Well-Known Policies  . . .  15
     4.1.  Private Use . . . . . . . . . . . . . . . . . . . . . . .  18
     4.2.  Experimental Use  . . . . . . . . . . . . . . . . . . . .  18
     4.3.  Hierarchical Allocation . . . . . . . . . . . . . . . . .  19
     4.4.  First Come First Served . . . . . . . . . . . . . . . . .  19
     4.5.  Expert Review . . . . . . . . . . . . . . . . . . . . . .  20
     4.6.  Specification Required  . . . . . . . . . . . . . . . . .  21
     4.7.  RFC Required  . . . . . . . . . . . . . . . . . . . . . .  22
     4.8.  IETF Review . . . . . . . . . . . . . . . . . . . . . . .  22
     4.9.  Standards Action  . . . . . . . . . . . . . . . . . . . .  23
     4.10. IESG Approval . . . . . . . . . . . . . . . . . . . . . .  23
     4.11. Using the Well-Known Registration Policies  . . . . . . .  24
     4.12. Using Multiple Policies in Combination  . . . . . . . . .  26
     4.13. Provisional Registrations . . . . . . . . . . . . . . . .  26

Top      ToC       Page 3 
   5.  Designated Experts  . . . . . . . . . . . . . . . . . . . . .  27
     5.1.  The Motivation for Designated Experts . . . . . . . . . .  27
     5.2.  The Role of the Designated Expert . . . . . . . . . . . .  27
       5.2.1.  Managing Designated Experts in the IETF . . . . . . .  29
     5.3.  Designated Expert Reviews . . . . . . . . . . . . . . . .  29
     5.4.  Expert Reviews and the Document Lifecycle . . . . . . . .  31
   6.  Well-Known Registration Status Terminology  . . . . . . . . .  31
   7.  Documentation References in IANA Registries . . . . . . . . .  32
   8.  What to Do in "bis" Documents . . . . . . . . . . . . . . . .  33
   9.  Miscellaneous Issues  . . . . . . . . . . . . . . . . . . . .  34
     9.1.  When There Are No IANA Actions  . . . . . . . . . . . . .  34
     9.2.  Namespaces Lacking Documented Guidance  . . . . . . . . .  35
     9.3.  After-the-Fact Registrations  . . . . . . . . . . . . . .  35
     9.4.  Reclaiming Assigned Values  . . . . . . . . . . . . . . .  35
     9.5.  Contact Person vs Assignee or Owner . . . . . . . . . . .  36
     9.6.  Closing or Obsoleting a Registry/Registrations  . . . . .  37
   10. Appeals . . . . . . . . . . . . . . . . . . . . . . . . . . .  37
   11. Mailing Lists . . . . . . . . . . . . . . . . . . . . . . . .  37
   12. Security Considerations . . . . . . . . . . . . . . . . . . .  37
   13. IANA Considerations . . . . . . . . . . . . . . . . . . . . .  38
   14. Changes Relative to Earlier Editions of BCP 26  . . . . . . .  38
     14.1.  2016: Changes in This Document Relative to RFC 5226  . .  38
     14.2.  2008: Changes in RFC 5226 Relative to RFC 2434 . . . . .  39
   15. References  . . . . . . . . . . . . . . . . . . . . . . . . .  40
     15.1.  Normative References . . . . . . . . . . . . . . . . . .  40
     15.2.  Informative References . . . . . . . . . . . . . . . . .  40
   Acknowledgments for This Document (2017)  . . . . . . . . . . . .  46
   Acknowledgments from the Second Edition (2008)  . . . . . . . . .  46
   Acknowledgments from the First Edition (1998) . . . . . . . . . .  46
   Authors' Addresses  . . . . . . . . . . . . . . . . . . . . . . .  47

Top      ToC       Page 4 
1.  Introduction

   Many protocols make use of points of extensibility that use constants
   to identify various protocol parameters.  To ensure that the values
   in these fields do not have conflicting uses and to promote
   interoperability, their allocations are often coordinated by a
   central record keeper.  The Protocol field in the IP header [RFC791]
   and MIME media types [RFC6838] are two examples of such

   The IETF selects an IANA Functions Operator (IFO) for protocol
   parameters defined by the IETF.  In the contract between the IETF and
   the current IFO (ICANN), that entity is referred to as the IANA
   PROTOCOL PARAMETER SERVICES Operator, or IPPSO.  For consistency with
   past practice, the IFO or IPPSO is referred to in this document as
   "IANA" [RFC2860].

   In this document, we call the range of possible values for such a
   field a "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, assigned value, code point,
   protocol constant, or protocol parameter).  The act of assignment is
   called a registration, and it takes place in the context of a
   registry.  The terms "assignment" and "registration" are used
   interchangeably throughout this document.

   To make assignments in a given namespace prudently, guidance
   describing the conditions under which new values should be assigned,
   as well as when and how modifications to existing values can be made,
   is needed.  This document defines a framework for the documentation
   of these guidelines by specification authors, in order to assure that
   the guidance for the IANA Considerations is clear and addresses the
   various issues that are likely in the operation of a registry.

   Typically, this information is recorded in a dedicated section of the
   specification with the title "IANA Considerations".

1.1.  Keep IANA Considerations for IANA

   The purpose of having a dedicated IANA Considerations section is to
   provide a single place to collect clear and concise information and
   instructions for IANA.  Technical documentation should reside in
   other parts of the document; the IANA Considerations should refer to
   these other sections by reference only (as needed).  Using the IANA
   Considerations section as primary technical documentation both hides
   it from the target audience of the document and interferes with
   IANA's review of the actions they need to take.

Top      ToC       Page 5 
   An ideal IANA Considerations section clearly enumerates and specifies
   each requested IANA action; includes all information IANA needs, such
   as the full names of all applicable registries; and includes clear
   references to elsewhere in the document for other information.

   The IANA actions are normally phrased as requests for IANA (such as,
   "IANA is asked to assign the value TBD1 from the Frobozz
   Registry..."); the RFC Editor will change those sentences to reflect
   the actions taken ("IANA has assigned the value 83 from the Frobozz

1.2.  For Updated Information

   IANA maintains a web page that includes additional clarification
   information beyond what is provided here, such as minor updates and
   summary guidance.  Document authors should check that page.  Any
   significant updates to the best current practice will have to feed
   into updates to BCP 26 (this document), which is definitive.


1.3.  A Quick Checklist Upfront

   It's useful to be familiar with this document as a whole.  But when
   you return for quick reference, here are checklists for the most
   common things you'll need to do and references to help with the less
   common ones.

   In general...

   1.  Put all the information that IANA will need to know into the
       "IANA Considerations" section of your document (see Section 1.1).

   2.  Try to keep that section only for information to IANA and to
       designated expert reviewers; put significant technical
       information in the appropriate technical sections of the document
       (see Section 1.1).

   3.  Note that the IESG has the authority to resolve issues with IANA
       registrations.  If you have any questions or problems, you should
       consult your document shepherd and/or working group chair, who
       may ultimately involve an Area Director (see Section 3.3).

Top      ToC       Page 6 
   If you are creating a new registry...

   1.  Give the registry a descriptive name and provide a brief
       description of its use (see Section 2.2).

   2.  Identify any registry grouping that it should be part of (see
       Section 2.1).

   3.  Clearly specify what information is required in order to register
       new items (see Section 2.2).  Be sure to specify data types,
       lengths, and valid ranges for fields.

   4.  Specify the initial set of items for the registry, if applicable
       (see Section 2.2).

   5.  Make sure the change control policy for the registry is clear to
       IANA, in case changes to the format or policies need to be made
       later (see Sections 2.3 and 9.5).

   6.  Select a registration policy -- or a set of policies -- to use
       for future registrations (see Section 4, and especially note
       Sections 4.11 and 4.12).

   7.  If you're using a policy that requires a designated expert
       (Expert Review or Specification Required), understand Section 5
       and provide review guidance to the designated expert (see
       Section 5.3).

   8.  If any items or ranges in your registry need to be reserved for
       special use or are otherwise unavailable for assignment, see
       Section 6.

   If you are registering into an existing registry...

   1.  Clearly identify the registry by its exact name and optionally by
       its URL (see Section 3.1).

   2.  If the registry has multiple ranges from which assignments can be
       made, make it clear which range is requested (see Section 3.1).

   3.  Avoid using specific values for numeric or bit assignments, and
       let IANA pick a suitable value at registration time (see
       Section 3.1).  This will avoid registration conflicts among
       multiple documents.

Top      ToC       Page 7 
   4.  For "reference" fields, use the document that provides the best
       and most current documentation for the item being registered.
       Include section numbers to make it easier for readers to locate
       the relevant documentation (see Sections 3.1 and 7).

   5.  Look up (in the registry's reference document) what information
       is required for the registry and accurately provide all the
       necessary information (see Section 3.1).

   6.  Look up (in the registry's reference document) any special rules
       or processes there may be for the registry, such as posting to a
       particular mailing list for comment, and be sure to follow the
       process (see Section 3.1).

   7.  If the registration policy for the registry does not already
       dictate the change control policy, make sure it's clear to IANA
       what the change control policy is for the item, in case changes
       to the registration need to be made later (see Section 9.5).

   If you're writing a "bis" document or otherwise making older
   documents obsolete, see Section 8.

   If you need to make an early registration, such as for supporting
   test implementations during document development, rather than waiting
   for your document to be finished and approved, see [RFC7120].

   If you need to change the format/contents or policies for an existing
   registry, see Section 2.4.

   If you need to update an existing registration, see Section 3.2.

   If you need to close down a registry because it is no longer needed,
   see Section 9.6.

2.  Creating and Revising Registries

   Defining a registry involves describing the namespaces to be created,
   listing an initial set of assignments (if applicable), and
   documenting guidelines on how future assignments are to be made.

   When defining a registry, consider structuring the namespace in such
   a way that only top-level assignments need to be made with central
   coordination, and those assignments can delegate lower-level
   assignments so coordination for them can be distributed.  This
   lessens the burden on IANA for dealing with assignments, and is
   particularly useful in situations where distributed coordinators have
   better knowledge of their portion of the namespace and are better
   suited to handling those assignments.

Top      ToC       Page 8 
2.1.  Organization of Registries

   All registries are anchored from the IANA "Protocol Registries" page:


   That page lists registries in protocol category groups, placing
   related registries together and making it easier for users of the
   registries to find the necessary information.  Clicking on the title
   of one of the registries on the IANA Protocol Registries page will
   take the reader to the details page for that registry.

   Unfortunately, we have been inconsistent in how we refer to these
   entities.  The group names, as they are referred to here, have been
   variously called "protocol category groups", "groups", "top-level
   registries", or just "registries".  The registries under them have
   been called "registries" or "sub-registries".

   Regardless of the terminology used, document authors should pay
   attention to the registry groupings, should request that related
   registries be grouped together to make related registries easier to
   find, and, when creating a new registry, should check whether that
   registry might best be included in an existing group.  That grouping
   information should be clearly communicated to IANA in the registry
   creation request.

2.2.  Documentation Requirements for Registries

   Documents that create a new namespace (or modify the definition of an
   existing space) and that expect IANA to play a role in maintaining
   that space (serving as a repository for registered values) must
   provide clear instructions on details of the namespace, either in the
   IANA Considerations section or referenced from it.

   In particular, such instructions must include:

   The name of the registry

      This name will appear on the IANA web page and will be referred to
      in future documents that need to allocate a value from the new
      space.  The full name (and abbreviation, if appropriate) should be
      provided.  It is highly desirable that the chosen name not be
      easily confused with the name of another registry.

      When creating a registry, the group that it is a part of must be
      identified using its full name, exactly as it appears in the
      Protocol Registries list.

Top      ToC       Page 9 
      Providing a URL to precisely identify the registry helps IANA
      understand the request.  Such URLs can be removed from the RFC
      prior to final publication or left in the document for reference.
      If you include URLs, IANA will provide corrections, if
      necessary, during their review.

   Required information for registrations

      This tells registrants what information they have to include in
      their registration requests.  Some registries require only the
      requested value and a reference to a document where use of the
      value is defined.  Other registries require a more detailed
      registration template that describes relevant security
      considerations, internationalization considerations, and other
      such information.

   Applicable registration policy

      The policy that will apply to all future requests for
      registration.  See Section 4.

   Size, format, and syntax of registry entries

      What fields to record in the registry, any technical requirements
      on registry entries (valid ranges for integers, length limitations
      on strings, and such), and the exact format in which registry
      values should be displayed.  For numeric assignments, one should
      specify whether values are to be recorded in decimal, in
      hexadecimal, or in some other format.

      Strings are expected to be ASCII, and it should be clearly
      specified whether case matters, and whether, for example, strings
      should be shown in the registry in uppercase or lowercase.

      Strings that represent protocol parameters will rarely, if ever,
      need to contain non-ASCII characters.  If non-ASCII characters are
      really necessary, instructions should make it very clear that they
      are allowed and that the non-ASCII characters should be
      represented as Unicode characters using the "(U+XXXX)" convention.
      Anyone creating such a registry should think carefully about this
      and consider internationalization advice such as that in
      [RFC7564], Section 10.

Top      ToC       Page 10 
   Initial assignments and reservations

      Any initial assignments or registrations to be included.  In
      addition, any ranges that are to be reserved for "Private Use",
      "Reserved", "Unassigned", etc. (see Section 6) should be

   For example, a document might specify a new registry by including:


     X. IANA Considerations

     This document defines a new DHCP option, entitled "FooBar" (see
     Section y), and assigns a value of TBD1 from the DHCP Option space
     [RFC2132] [RFC2939]:
           Tag     Name            Length      Meaning
           ----    ----            ------      -------
           TBD1    FooBar          N           FooBar server

     The FooBar option also defines an 8-bit FooType field, for which
     IANA is to create and maintain a new registry entitled
     "FooType values" used by the FooBar option.  Initial values for the
     DHCP FooBar FooType registry are given below; future assignments
     are to be made through Expert Review [BCP26].  Assignments consist
     of a DHCP FooBar FooType name and its associated value.

           Value    DHCP FooBar FooType Name   Definition
           ----     ------------------------   ----------
           0        Reserved
           1        Frobnitz                   RFCXXXX, Section y.1
           2        NitzFrob                   RFCXXXX, Section y.2
           3-254    Unassigned
           255      Reserved

   For examples of documents that establish registries, consult
   [RFC3575], [RFC3968], and [RFC4520].

   Any time IANA includes names and contact information in the public
   registry, some individuals might prefer that their contact
   information not be made public.  In such cases, arrangements can be
   made with IANA to keep the contact information private.

Top      ToC       Page 11 
2.3.  Specifying Change Control for a Registry

   Registry definitions and registrations within registries often need
   to be changed after they are created.  The process of making such
   changes is complicated when it is unclear who is authorized to make
   the changes.  For registries created by RFCs in the IETF stream,
   change control for the registry lies by default with the IETF, via
   the IESG.  The same is true for value registrations made in IETF-
   stream RFCs.

   Because registries can be created and registrations can be made
   outside the IETF stream, it can sometimes be desirable to have change
   control outside the IETF and IESG, and clear specification of change
   control policies is always helpful.

   It is advised, therefore, that all registries that are created
   clearly specify a change control policy and a change controller.  It
   is also advised that registries that allow registrations from outside
   the IETF stream include, for each value, the designation of a change
   controller for that value.  If the definition or reference for a
   registered value ever needs to change, or if a registered value needs
   to be deprecated, it is critical that IANA know who is authorized to
   make the change.  For example, the Media Types registry [RFC6838]
   includes a "Change Controller" in its registration template.  See
   also Section 9.5.

2.4.  Revising Existing Registries

   Updating the registration process or making changes to the format of
   an already existing (previously created) registry (whether created
   explicitly or implicitly) follows a process similar to that used when
   creating a new registry.  That is, a document is produced that makes
   reference to the existing namespace and then provides detailed
   guidance for handling assignments in the registry or detailed
   instructions about the changes required.

   If a change requires a new column in the registry, the instructions
   need to be clear about how to populate that column for the existing
   entries.  Other changes may require similar clarity.

   Such documents are normally processed with the same document status
   as the document that created the registry.  Under some circumstances,
   such as with a straightforward change that is clearly needed (such as
   adding a "status" column), or when an earlier error needs to be
   corrected, the IESG may approve an update to a registry without
   requiring a new document.

Top      ToC       Page 12 
   Example documents that updated the guidelines for assignments in
   pre-existing registries include: [RFC6895], [RFC3228], and [RFC3575].

3.  Registering New Values in an Existing Registry

3.1.  Documentation Requirements for Registrations

   Often, documents request an assignment in an existing registry (one
   created by a previously published document).

   Such documents should clearly identify the registry into which each
   value is to be registered.  Use the exact registry name as listed on
   the IANA web page, and cite the RFC where the registry is defined.
   When referring to an existing registry, providing a URL to precisely
   identify the registry is helpful (see Section 2.2).

   There is no need to mention what the assignment policy is when making
   new assignments in existing registries, as that should be clear from
   the references.  However, if multiple assignment policies might
   apply, as in registries with different ranges that have different
   policies, it is important to make it clear which range is being
   requested, so that IANA will know which policy applies and can assign
   a value in the correct range.

   Be sure to provide all the information required for a registration,
   and follow any special processes that are set out for the registry.
   Registries sometimes require the completion of a registration
   template for registration or ask registrants to post their request to
   a particular mailing list for discussion prior to registration.  Look
   up the registry's reference document: the required information and
   special processes should be documented there.

   Normally, numeric values to be used are chosen by IANA when the
   document is approved; drafts should not specify final values.
   Instead, placeholders such as "TBD1" and "TBD2" should be used
   consistently throughout the document, giving each item to be
   registered a different placeholder.  The IANA Considerations should
   ask the RFC Editor to replace the placeholder names with the IANA-
   assigned values.  When drafts need to specify numeric values for
   testing or early implementations, they will either request early
   allocation (see Section 3.4) or use values that have already been set
   aside for testing or experimentation (if the registry in question
   allows that without explicit assignment).  It is important that
   drafts not choose their own values, lest IANA assign one of those
   values to another document in the meantime.  A draft can request a
   specific value in the IANA Considerations section, and IANA will

Top      ToC       Page 13 
   accommodate such requests when possible, but the proposed number
   might have been assigned to some other use by the time the draft is

   Normally, text-string values to be used are specified in the
   document, as collisions are less likely with text strings.  IANA will
   consult with the authors if there is, in fact, a collision, and a
   different value has to be used.  When drafts need to specify string
   values for testing or early implementations, they sometimes use the
   expected final value.  But it is often useful to use a draft value
   instead, possibly including the draft version number.  This allows
   the early implementations to be distinguished from those implementing
   the final version.  A document that intends to use "foobar" in the
   final version might use "foobar-testing-draft-05" for the -05 version
   of the draft, for example.

   For some registries, there is a long-standing policy prohibiting
   assignment of names or codes on a vanity or organization-name basis.
   For example, codes might always be 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

   As an example, the following text could be used to request assignment
   of a DHCPv6 option number:

      IANA is asked to assign 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.

   The IANA Considerations section should summarize all of the IANA
   actions, with pointers to the relevant sections elsewhere in the
   document as appropriate.  Including section numbers is especially
   useful when the reference document is large; the section numbers will
   make it easier for those searching the reference document to find the
   relevant information.

   When multiple values are requested, it is generally helpful to
   include a summary table of the additions/changes.  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, Section 3.2
     TBD2      Gumbo                this RFC, Section 3.3
     TBD3      Banana               this RFC, Section 3.4

Top      ToC       Page 14 
   Note: In cases where authors feel that including the full table of
   changes 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.

3.2.  Updating Existing Registrations

   Even after a number has been assigned, some types of registrations
   contain additional information that may need to be updated over time.

   For example, MIME media types, character sets, and language tags
   typically include more information than just the registered value
   itself, and may need updates to items such as point-of-contact
   information, security issues, pointers to updates, and literature

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

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

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

   o  Designating the IESG, a designated expert, or another entity as
      having the right to change the registrant associated with a
      registration and any requirements or conditions on doing so.  This
      is mainly to get around the problem when a registrant cannot be
      reached in order to make necessary updates.

3.3.  Overriding Registration Procedures

   Experience has shown that the documented IANA considerations for
   individual protocols do not always adequately cover the reality of
   registry operation or are not sufficiently clear.  In addition,
   documented IANA considerations are sometimes found to be too
   stringent to allow even working group documents (for which there is
   strong consensus) to perform a registration in advance of actual RFC

Top      ToC       Page 15 
   In order to allow assignments in such cases, the IESG is granted
   authority to override registration procedures and approve assignments
   on a case-by-case basis.

   The intention here is not to overrule properly documented procedures
   or to obviate the need for protocols to properly document their IANA
   considerations.  Rather, it is to permit assignments in specific
   cases where it is obvious that the assignment should just be made,
   but updating the IANA process beforehand is too onerous.

   When the IESG is required to take action as described above, it is a
   strong indicator that the applicable registration procedures should
   be updated, possibly in parallel with the work that instigated it.

   IANA always has the discretion to ask the IESG for advice or
   intervention when they feel it is needed, such as in cases where
   policies or procedures are unclear to them, where they encounter
   issues or questions they are unable to resolve, or where registration
   requests or patterns of requests appear to be unusual or abusive.

3.4.  Early Allocations

   IANA normally takes its actions when a document is approved for
   publication.  There are times, though, when early allocation of a
   value is important for the development of a technology, for example,
   when early implementations are created while the document is still
   under development.

   IANA has a mechanism for handling such early allocations in some
   cases.  See [RFC7120] for details.  It is usually not necessary to
   explicitly mark a registry as allowing early allocation, because the
   general rules will apply.

(page 15 continued on part 2)

Next Section