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Run idnits with the --verbose option for more detailed information about the items above. -------------------------------------------------------------------------------- 2 Network Working Group M. Cotton 3 Internet-Draft ICANN 4 BCP: 26 B. Leiba 5 Obsoletes: 5226 (if approved) Huawei Technologies 6 Intended status: Best Current Practice T. Narten 7 Expires: January 02, 2015 IBM Corporation 8 July 03, 2014 10 Guidelines for Writing an IANA Considerations Section in RFCs 11 draft-leiba-cotton-iana-5226bis-06 13 Abstract 15 Many protocols make use of points of extensibility that use constants 16 to identify various protocol parameters. To ensure that the values 17 used in these fields do not have conflicting uses, and to promote 18 interoperability, their allocation is often coordinated by a central 19 authority. For IETF protocols, that role is filled by the Internet 20 Assigned Numbers Authority (IANA). 22 To make assignments in a given namespace prudently, IANA needs 23 guidance describing the conditions under which new values should be 24 assigned, as well as when and how modifications to existing values 25 can be made. This document defines a framework for the documentation 26 of these guidelines by specification authors, in order to assure that 27 the guidance given to IANA is clear and addresses the various issues 28 that are likely in the operation of a registry. 30 This is the third edition, and obsoletes RFC 5226. 32 Status of this Memo 34 This Internet-Draft is submitted in full conformance with the 35 provisions of BCP 78 and BCP 79. 37 Internet-Drafts are working documents of the Internet Engineering 38 Task Force (IETF). Note that other groups may also distribute 39 working documents as Internet-Drafts. The list of current Internet- 40 Drafts is at http://datatracker.ietf.org/drafts/current/. 42 Internet-Drafts are draft documents valid for a maximum of six months 43 and may be updated, replaced, or obsoleted by other documents at any 44 time. It is inappropriate to use Internet-Drafts as reference 45 material or to cite them other than as "work in progress." 47 This Internet-Draft will expire on January 02, 2015. 49 Copyright Notice 51 Copyright (c) 2014 IETF Trust and the persons identified as the 52 document authors. All rights reserved. 54 This document is subject to BCP 78 and the IETF Trust's Legal 55 Provisions Relating to IETF Documents (http://trustee.ietf.org/ 56 license-info) in effect on the date of publication of this document. 57 Please review these documents carefully, as they describe your rights 58 and restrictions with respect to this document. Code Components 59 extracted from this document must include Simplified BSD License text 60 as described in Section 4.e of the Trust Legal Provisions and are 61 provided without warranty as described in the Simplified BSD License. 63 Table of Contents 65 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 3 66 1.1. Keep IANA Considerations for IANA . . . . . . . . . . . . 3 67 1.2. For More Information . . . . . . . . . . . . . . . . . . . 4 68 1.3. Terminology Used In This Document . . . . . . . . . . . . 4 69 2. Creating and Revising Registries . . . . . . . . . . . . . . . 4 70 2.1. Hierarchical Registry Structure . . . . . . . . . . . . . 5 71 2.2. Documentation Requirements for Registries . . . . . . . . 6 72 2.3. Defining an Appropriate Registry Policy . . . . . . . . . 8 73 2.3.1. Using the Well-Known Registration Policies . . . . . . 10 74 2.3.2. Using Multiple Policies in Combination . . . . . . . . 11 75 2.3.3. Specifying Change Control for a Registry . . . . . . . 12 76 2.4. Revising Existing Registries . . . . . . . . . . . . . . . 12 77 3. Registering New Values in an Existing Registry . . . . . . . . 13 78 3.1. Documentation Requirements for Registrations . . . . . . . 13 79 3.2. Updating Existing Registrations . . . . . . . . . . . . . 14 80 3.3. Overriding Registration Procedures . . . . . . . . . . . . 15 81 3.4. Early Allocations . . . . . . . . . . . . . . . . . . . . 15 82 4. Well-Known Registration Policies . . . . . . . . . . . . . . . 15 83 4.1. Private Use . . . . . . . . . . . . . . . . . . . . . . . 16 84 4.2. Experimental Use . . . . . . . . . . . . . . . . . . . . . 17 85 4.3. Hierarchical Allocation . . . . . . . . . . . . . . . . . 17 86 4.4. First Come First Served . . . . . . . . . . . . . . . . . 17 87 4.5. Expert Review . . . . . . . . . . . . . . . . . . . . . . 17 88 4.6. Specification Required . . . . . . . . . . . . . . . . . . 18 89 4.7. RFC Required . . . . . . . . . . . . . . . . . . . . . . . 19 90 4.8. IETF Review . . . . . . . . . . . . . . . . . . . . . . . 19 91 4.9. Standards Action . . . . . . . . . . . . . . . . . . . . . 19 92 4.10. IESG Approval . . . . . . . . . . . . . . . . . . . . . . 19 93 5. Designated Experts . . . . . . . . . . . . . . . . . . . . . . 20 94 5.1. The Motivation for Designated Experts . . . . . . . . . . 20 95 5.2. The Role of the Designated Expert . . . . . . . . . . . . 21 96 5.3. Designated Expert Reviews . . . . . . . . . . . . . . . . 22 97 5.4. Expert Reviews and the Document Lifecycle . . . . . . . . 24 98 6. Well-Known Registration Status Terminology . . . . . . . . . . 24 99 7. Documentation References in IANA Registries . . . . . . . . . 25 100 8. What to Do in "bis" Documents . . . . . . . . . . . . . . . . 25 101 9. Miscellaneous Issues . . . . . . . . . . . . . . . . . . . . . 26 102 9.1. When There Are No IANA Actions . . . . . . . . . . . . . . 26 103 9.2. Namespaces Lacking Documented Guidance . . . . . . . . . . 27 104 9.3. After-the-Fact Registrations . . . . . . . . . . . . . . . 27 105 9.4. Reclaiming Assigned Values . . . . . . . . . . . . . . . . 28 106 9.5. Contact Person vs Assignee or Owner . . . . . . . . . . . 28 107 9.6. Closing or Obsoleting a Registry . . . . . . . . . . . . . 29 108 10. Appeals . . . . . . . . . . . . . . . . . . . . . . . . . . . 29 109 11. Mailing Lists . . . . . . . . . . . . . . . . . . . . . . . . 29 110 12. Security Considerations . . . . . . . . . . . . . . . . . . . 29 111 13. Changes Relative to Earlier Editions of BCP 26 . . . . . . . . 30 112 13.1. 2014: Changes in This Document Relative to RFC 5226 . . . 30 113 13.2. 2008: Changes in RFC 5226 Relative to RFC 2434 . . . . . 31 114 14. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . 32 115 14.1. Acknowledgments for This Document (2014) . . . . . . . . 32 116 14.2. Acknowledgments from the second edition (2008) . . . . . 32 117 14.3. Acknowledgments from the first edition (1998) . . . . . . 32 118 15. References . . . . . . . . . . . . . . . . . . . . . . . . . . 32 119 15.1. Normative References . . . . . . . . . . . . . . . . . . 32 120 15.2. Informative References . . . . . . . . . . . . . . . . . 33 121 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 35 123 1. Introduction 125 Many protocols make use of points of extensibility that use constants 126 to identify various protocol parameters. To ensure that the values 127 used in these fields do not have conflicting uses, and to promote 128 interoperability, their allocation is often coordinated by a central 129 authority. For IETF protocols, that role is filled by the Internet 130 Assigned Numbers Authority (IANA) [RFC2860]. IANA services are 131 currently provided by the International Corporation for Assigned 132 Names and Numbers (ICANN). 134 The Protocol field in the IP header [RFC0791] and MIME media types 135 [RFC4288] are two examples of such coordinations. 137 In this document, we call the range of possible values for such a 138 field a "namespace". The binding or association of a specific value 139 with a particular purpose within a namespace is called an assignment 140 (or, variously: an assigned number, assigned value, code point, 141 protocol constant, or protocol parameter). The act of assignment is 142 called a registration, and it takes place in the context of a 143 registry. The terms "assignment" and "registration" are used 144 interchangably throughout this document. 146 To make assignments in a given namespace prudently, IANA needs 147 guidance describing the conditions under which new values should be 148 assigned, as well as when and how modifications to existing values 149 can be made. This document defines a framework for the documentation 150 of these guidelines by specification authors, in order to assure that 151 the guidance given to IANA is clear and addresses the various issues 152 that are likely in the operation of a registry. 154 Typically, this information is recorded in a dedicated section of the 155 specification with the title "IANA Considerations". 157 1.1. Keep IANA Considerations for IANA 158 The purpose of having a dedicated IANA Considerations section is to 159 provide a single place to collect clear and concise information and 160 instructions for IANA. Technical documentation should reside in 161 other parts of the document, and should be included by reference 162 only. Using the IANA Considerations section as primary technical 163 documentation both hides it from the target audience of the document 164 and interferes with IANA's review of the actions they need to take. 166 If, for example, the registration of an item in a registry includes a 167 short description of the item being registered, that should be placed 168 in the IANA Considerations directly. But if it's necessary to 169 include a longer technical explanation of the purpose and use of the 170 item, the IANA Considerations should refer to a technical section of 171 the document where that information resides. Similarly, if the 172 document is pointing out the use of an existing assignment in a 173 registry, but makes no modification to the registration, that should 174 be in a technical section of the document, reserving the IANA 175 Considerations section for instructions to IANA. 177 An ideal IANA Considerations section clearly enumerates and specifies 178 each requested IANA action; includes all information IANA needs, such 179 as the full names of all applicable registries; and includes clear 180 references to elsewhere in the document for other information. 182 1.2. For More Information 184 IANA maintains a web page that includes current important information 185 from IANA. Document authors should check that page for additional 186 information, beyond what is provided here. 188 . 190 [[***** The URI above is not yet ready. IANA is setting it up. 191 *****]] 193 1.3. Terminology Used In This Document 195 The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", 196 "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this 197 document are to be interpreted as described in RFC 2119 [RFC2119]. 198 For this document, "the specification" as used by RFC 2119 refers to 199 the processing of protocol documents within the IETF standards 200 process. 202 2. Creating and Revising Registries 204 Defining a registry involves describing the namespace(s) to be 205 created, listing an initial set of assignments (if appropriate), and 206 documenting guidelines on how future assignments are to be made. 208 Before defining a registry, however, consider delegating the 209 namespace in some manner. This route should be pursued when 210 appropriate, as it lessens the burden on IANA for dealing with 211 assignments. 213 In particular, not all namespaces require a registry; in some cases, 214 assignments can be made independently and with no further (central) 215 coordination. In the Domain Name System, for example, IANA only 216 deals with assignments at the higher levels, while subdomains are 217 administered by the organization to which the space has been 218 delegated. When a namespace is delegated in this manner, the scope 219 of IANA is limited to the parts of the namespace where IANA has 220 authority. 222 2.1. Hierarchical Registry Structure 224 It's important to start with a word on the IANA registry structure. 225 All registries are anchored from the IANA "Protocol Registries" page: 227 . 229 That page lists registries in groups, like this: 231 --------------------------------------------------------------- 232 Author Domain Signing Practices (ADSP) Parameters 234 ADSP Outbound Signing Practices RFC 5617 235 IETF Review 237 ADSP Specification Tags RFC 5617 238 IETF Review 240 Automatic Responses to Electronic Mail Parameters 242 Auto-Submitted Header Field RFC 5436 243 Keywords Specification Required 245 Auto-Submitted header field RFC 3834 246 optional parameters IETF Consensus 248 Autonomous System (AS) Numbers 250 16-bit Autonomous System Numbers RFC 1930, RFC 5398, RFC 6996 251 RIR request to the IANA 252 or IETF Review 254 32-bit Autonomous System Numbers RFC 1930, RFC 5398, RFC 6793, 255 RFC 6996 256 RIR request to the IANA 257 or IETF Review 258 --------------------------------------------------------------- 260 The grouping allows related registries to be placed together, making 261 it easier for users of the registries to find the necessary 262 information. In the example section above, there are two registries 263 related to the ADSP protocol, and they are both placed in the "ADSP 264 Parameters" group. 266 Within the "ADSP Parameters" group are two registries: "ADSP Outbound 267 Signing Practices" and "ADSP Specification Tags". Clicking on the 268 title of one of these registries on the IANA Protocol Registries page 269 will take the reader to the details page for that registry. Often, 270 multiple registries are shown on the same details page. 272 Unfortunately, we have been inconsistent in how we refer to these 273 entities. The group names, as they are referred to here, have been 274 variously called "groups", "top-level registries", or just 275 "registries". The registries under them have been called 276 "registries" or "sub-registries". And when new registries are 277 created, the documents that define them often don't specify the 278 grouping at all, but only name the new registry. This results in 279 questions from IANA and delays in processing, or, worse, in related 280 registries that should have been grouped together, but that are 281 instead scattered about and hard to find and correlate. 283 Regardless of the terminology used, document authors should pay 284 attention to the registry groupings, should request that related 285 registries be grouped together, and, when creating a new registry, 286 should check whether that registry might best be included in an 287 existing group. That grouping information should be clearly 288 communicated to IANA in the registry creation request. 290 2.2. Documentation Requirements for Registries 292 Documents that create a new namespace (or modify the definition of an 293 existing space) and that expect IANA to play a role in maintaining 294 that space (serving as a repository for registered values) MUST 295 provide clear instructions on details of the namespace, either in the 296 IANA Considerations section, or referenced from it. 298 In particular, such instructions MUST include: 300 The name of the registry (or sub-registry) 301 This name will appear on the IANA web page and will be referred to 302 in future documents that need to allocate a value from the new 303 space. The full name (and abbreviation, if appropriate) should be 304 provided. It is highly desirable that the chosen name not be 305 easily confused with the name of another registry. 307 When creating a sub-registry, the registry that it is a part of 308 must be identified using its full name, exactly as it appears in 309 the IANA registry list. 311 Providing a URL to precisely identify the registry helps IANA 312 understand the request. Such URLs can be removed from the RFC 313 prior to final publication. If they are to be left in, it is 314 important that they be permanent links -- IANA intends to include 315 the permalink for each registry in the registry header. [[***** 316 This is not yet done, but is planned. *****]] 318 For example, a document could contain something like this: 320 This registration should be made in the Foobar Operational 321 Parameters registry, located at . 324 It might be tempting to use the URL that appears in your web 325 browser's address bar, which might look something like this for 326 the example above: 328 http://www.iana.org/assignments/foobar-registry/foobar- 329 registry.xml 331 ...but that is not the permanent link to the registry. 333 Required information for registrations 335 This information may include the need to document relevant 336 Security Considerations, if any. 338 Applicable review process 340 The review process that will apply to all future requests for 341 registration. See Section 2.3. 343 Size, format and syntax of registry entries 345 What fields to record in the registry., and any technical 346 requirements upon registry entries (e.g., valid ranges for 347 integers, length limitations on strings, etc.) as well as the 348 exact format in which registry values should be displayed. For 349 numeric assignments, one should specify whether values are to be 350 recorded in decimal, hexadecimal, or some other format. For 351 strings, the encoding format should be specified (ASCII, UTF8, 352 etc.). 354 Initial assignments and reservations 356 Any initial assignments or registrations to be included. In 357 addition, any ranges that are to be reserved for "Private Use", 358 "Reserved", "Unassigned", etc. should be indicated. 360 For example, a document might specify a new registry by including: 362 --------------------------------------------------------------- 364 X. IANA Considerations 366 This document defines a new DHCP option, entitled "FooBar" (see 367 Section y), assigned a value of TBD1 from the DHCP Option space 368 [to be removed upon publication: 369 http://www.iana.org/assignments/bootp-dhcp-parameters] 370 [RFC2132] [RFC2939]: 371 Data 372 Tag Name Length Meaning 373 ---- ---- ------ ------- 374 TBD1 FooBar N FooBar server 376 The FooBar option also defines an 8-bit FooType field, for which 377 IANA is to create and maintain a new sub-registry entitled 378 "FooType values" under the FooBar option. Initial values for the 379 DHCP FooBar FooType registry are given below; future assignments 380 are to be made through Expert Review [BCP26]. 381 Assignments consist of a DHCP FooBar FooType name and its 382 associated value. 384 Value DHCP FooBar FooType Name Definition 385 ---- ------------------------ ---------- 386 0 Reserved 387 1 Frobnitz See Section y.1 388 2 NitzFrob See Section y.2 389 3-254 Unassigned 390 255 Reserved 391 --------------------------------------------------------------- 393 For examples of documents that establish registries, consult 394 [RFC6195], [RFC3575], [RFC3968], and [RFC4520]. 396 2.3. Defining an Appropriate Registry Policy 398 There are several issues to consider when defining the policy for the 399 new assignments in a registry. 401 If the registry's namespace is limited, assignments will need to be 402 made carefully to prevent exhaustion. 404 Even when the space is essentially unlimited, however, it is usually 405 desirable to have at least a minimal review prior to assignment in 406 order to: 408 o prevent the hoarding of or unnecessary wasting of values. For 409 example, if the space consists of text strings, it may be 410 desirable to prevent entities from obtaining large sets of strings 411 that correspond to desirable names (existing company names, for 412 example). 414 o provide a sanity check that the request actually makes sense and 415 is necessary. Experience has shown that some level of minimal 416 review from a subject matter expert is useful to prevent 417 assignments in cases where the request is malformed or not 418 actually needed (for example, an existing assignment for an 419 essentially equivalent service already exists). 421 Perhaps most importantly, unreviewed extensions can impact 422 interoperability and security. See [RFC6709]. 424 When the namespace is essentially unlimited and there are no 425 potential interoperability or security issues, assigned numbers can 426 usually be given out to anyone without any subjective review. In 427 such cases, IANA can make assignments directly, provided that IANA is 428 given detailed instructions on what types of requests it should 429 grant, and it is able to do so without exercising subjective 430 judgement. 432 When this is not the case, some level of review is required. 433 However, it's important to balance adequate review and ease of 434 registration. In many cases, those making registrations will not be 435 IETF participants; requests often come from other standards 436 organizations, from organizations not directly involved in standards, 437 from ad-hoc community work (from an open-source project, for 438 example), and so on. Registration must not be unnecessarily 439 difficult, unnecessarily costly (in terms of time and other 440 resources), nor unnecessarily subject to denial. 442 While it is sometimes necessary to restrict what gets registered 443 (e.g., for limited resources such as bits in a byte, or for items for 444 which unsupported values can be damaging to protocol operation), in 445 many cases having what's in use represented in the registry is more 446 important. Overly strict review criteria and excessive cost (in time 447 and effort) discourage people from even attempting to make a 448 registration. If a registry fails to reflect the protocol elements 449 actually in use, it can adversely affect deployment of protocols on 450 the Internet, and the registry itself is devalued. 452 In particular, when a registry policy that requires involvement of 453 Working Groups, directorates, or other bodies to be actively involved 454 and to support the effort, requests frequently run into concerns that 455 "it's not worth doing a Standards-Track RFC for something this 456 trivial," when, in fact, that requirement was created by the Working 457 Group in the first place, by placing the bar that high. 459 Indeed, publishing any RFC is costly, and a Standards Track RFC is 460 especially so, requiring a great deal of community time for review 461 and discussion, IETF-wide last call, involvement of the entire IESG 462 as well as concentrated time and review from the sponsoring AD, 463 review and action by IANA, and RFC-Editor processing. 465 Therefore, Working Groups and other document developers should use 466 care in selecting appropriate registration policies when their 467 documents create registries. They should select the least strict 468 policy that suits a registry's needs, and look for specific 469 justification for policies that require significant community 470 involvement (Specification Required, in terms of the well-known 471 policies). 473 2.3.1. Using the Well-Known Registration Policies 475 This document defines a number of registration policies in Section 4. 476 Because they benefit from both community experience and wide 477 understanding, their use is encouraged when appropriate. 479 It is also acceptable to cite one of the well-known policies and 480 include additional guidelines for what kind of considerations should 481 be taken into account by the review process. 483 For example, RADIUS [RFC3575] specifies the use of a Designated 484 Expert, but includes specific additional criteria the Designated 485 Expert should follow. 487 The well-known policies from "First Come First Served" to "Standards 488 Action" specify a range of policies in increasing order of 489 strictness: 491 4. First Come First Served 492 No review, minimal documentation. 494 5. Expert Review 495 Expert review, sufficient documentation for review. 497 6. Specification Required 498 Expert review, significant, stable public documentation. 500 7. RFC Required 501 Any RFC publication, IETF or a non-IETF Stream. 503 8. IETF Review 504 RFC publication, IETF Stream only, but need not be Standards 505 Track. 507 9. Standards Action 508 RFC publication, IETF Stream, Standards Track only. 510 Examples of situations that might merit RFC Required, IETF Review, or 511 Standards Action include the following: 513 o When a resource is limited, such as bits in a byte (or in two 514 bytes, or four), or numbers in a limited range. In these cases, 515 allowing registrations that haven't been carefully reviewed and 516 agreed by community consensus could too quickly deplete the 517 allowable values. 519 o When thorough community review is necessary to avoid extending or 520 modifying the protocol in ways that could be damaging. One 521 example is in defining new command codes, as opposed to options 522 that use existing command codes: the former might require a strict 523 policy, where a more relaxed policy could be adequate for the 524 latter. Another example is in defining protocol elements that 525 change the semantics of existing operations. 527 The description in Section 4.10 of "IESG Approval" suggests that the 528 IESG "can (and should) reject a request if another path for 529 registration is available that is more appropriate and there is no 530 compelling reason not to use that path." The IESG should give 531 similar consideration to any registration policy more stringent than 532 Specification Required, asking for justification and ensuring that 533 more relaxed policies have been considered, and the strict policy is 534 the right one. 536 Accordingly, document developers need to anticipate this and document 537 their considerations for selecting the specified policy (ideally, in 538 the document itself; failing that, in the shepherd writeup). 539 Likewise, the document shepherd should ensure that the selected 540 policies have been justified before sending the document to the IESG. 542 When specifications are revised, registration policies should be 543 reviewed in light of experience since the policies were set. 545 Note that the well-known policies are not exclusive; there are 546 situations where a different policy might be more appropriate. 548 2.3.2. Using Multiple Policies in Combination 550 In some situations, it is necessary to define multiple registration 551 policies. For example, registrations through the normal IETF process 552 might use one policy, while registrations from outside the process 553 would have a different policy applied. 555 Thus, a particular registry might want to use a policy such as "RFC 556 Required" or "IETF Review" sometimes, with a designated expert 557 checking a "Specification Required" policy at other times. 559 The alternative to using a combination requires either that all 560 requests come through RFCs or that requests in RFCs go through review 561 by the designated expert, even though they already have IETF review 562 and consensus. 564 This can be documented in the IANA Considerations section when the 565 registry is created: 567 IANA is asked to create the registry "Fruit Access Flags" as a 568 sub-registry of "Fruit Parameters". New registrations will be 569 permitted through either the IETF Review policy or the 570 Specification Required policy [BCP26]. 572 Such combinations will commonly use one of {Standards Action, IETF 573 Review, RFC Required} in combination with one of {Specification 574 Required, Expert Review}. 576 2.3.3. Specifying Change Control for a Registry 578 Registry definitions and registrations within registries often need 579 to be changed after they are created. The process of making such 580 changes is complicated when it is unclear who is authorized to make 581 the changes. For registries created by RFCs in the IETF stream, 582 change control for the registry lies by default with the IETF, via 583 the IESG. The same is true for value registrations made in IETF- 584 stream RFCs. 586 But registries can be created and registrations can be made outside 587 the IETF stream, it can sometimes be desired to have change control 588 outside the IETF and IESG, and clear specification of change control 589 policies is always helpful. 591 It is advised, therefore, that all registries that are created 592 clearly specify a change control policy and a change controller. It 593 is also advised that registries that allow registrations from outside 594 the IETF stream include, for each value, the designation of a change 595 controller for that value. If the definition or reference for a 596 registered value ever needs to change, or if a registered value needs 597 to be deprecated, it is critical that IANA know who is authorized to 598 make the change. See also Section 9.5. 600 2.4. Revising Existing Registries 602 Updating the registration process or making changes to the format of 603 an already existing (previously created) registry (whether created 604 explicitly or implicitly) follows a process similar to that used when 605 creating a new registry. That is, a document is produced that makes 606 reference to the existing namespace and then provides detailed 607 guidance for handling assignments in the registry, or detailed 608 instructions about the changes required. 610 If a change requires a new column in the registry, the instructions 611 need to be clear about how to populate that column for the existing 612 entries. Other changes may require similar clarity. Remember to 613 check this, and give clear instructions to IANA. 615 Such documents are normally processed with the same document status 616 as the document that created the registry, or as Best Current 617 Practices (BCPs) [RFC2026]. 619 Example documents that updated the guidelines for assignments in pre- 620 existing registries include: [RFC6195], [RFC3228], and [RFC3575]. 622 3. Registering New Values in an Existing Registry 624 3.1. Documentation Requirements for Registrations 626 Often, documents request an assignment from an already existing 627 namespace (one created by a previously published document). 629 Such documents should clearly identify the namespace in which each 630 value is to be registered. If the registration goes into a sub- 631 registry, the author should clearly describe where the assignment or 632 registration should go. Use the exact namespace name as listed on 633 the IANA web page, and cite the RFC where the namespace is defined. 635 There is no need to mention what the assignment policy for new 636 assignments is, as that should be clear from the references. 638 When referring to an existing registry, providing a URL to precisely 639 identify the registry is helpful. See Section 2.2 for details on 640 specifying the correct URL. 642 For example, a document could contain something like this: 644 This registration should be made in the Foobar Operational 645 Parameters registry, located at . 648 Each value requested should be given a unique reference. When the 649 value is numeric, use the notation: TBD1, TBD2, etc. Throughout the 650 document where an actual IANA-assigned value should be filled in, use 651 the "TBDx" notation. This helps ensure that the final RFC has the 652 correct assigned values inserted in all of the relevant places where 653 the value is expected to appear in the final document. For values 654 that are text strings, a specific name can be suggested. IANA will 655 normally assign the name, unless it conflicts with a name already in 656 use. 658 Normally, the values to be used are chosen by IANA and documents 659 should specify values of "TBD". However, in some cases, a value may 660 have been used for testing or in early implementations. In such 661 cases, it is acceptable to include text suggesting what specific 662 value should be used (together with the reason for the choice). For 663 example, one might include the text "the value XXX is suggested as it 664 is used in implementations". However, it should be noted that 665 suggested values are just that; IANA will attempt to assign them, but 666 may find that impossible, if the proposed number has already been 667 assigned for some other use. 669 For some registries, IANA has a long-standing policy prohibiting 670 assignment of names or codes on a vanity or organization-name basis. 671 For example, codes are always assigned sequentially unless there is a 672 strong reason for making an exception. Nothing in this document is 673 intended to change those policies or prevent their future 674 application. 676 The IANA Considerations section should summarize all of the IANA 677 actions, with pointers to the relevant sections elsewhere in the 678 document as appropriate. When multiple values are requested, it is 679 generally helpful to include a summary table. It is also helpful for 680 this table to be in the same format as it appears or will appear on 681 the IANA web site. For example: 683 Value Description Reference 684 -------- ------------------- --------- 685 TBD1 Foobar [[this RFC]] 687 Note: In cases where authors feel that including the full table is 688 too verbose or repetitive, authors should still include the table in 689 the draft, but may include a note asking that the table be removed 690 prior to publication of the final RFC. 692 As an example, the following text could be used to request assignment 693 of a DHCPv6 option number: 695 IANA has assigned an option code value of TBD1 to the DNS 696 Recursive Name Server option and an option code value of TBD2 to 697 the Domain Search List option from the DHCP option code space 698 defined in Section 24.3 of RFC 3315. 700 3.2. Updating Existing Registrations 702 Even after a number has been assigned, some types of registrations 703 contain additional information that may need to be updated over time. 705 For example, MIME media types, character sets, and language tags 706 typically include more information than just the registered value 707 itself, and may need things such as point-of-contact information, 708 security issues, pointers to updates, or literature references 709 updated. 711 In such cases, the document defining the namespace must clearly state 712 who is responsible for maintaining and updating a registration. 713 Depending on the registry, it may be appropriate to specify one or 714 more of: 716 o Letting registrants and/or nominated change controllers update 717 their own registrations, subject to the same constraints and 718 review as with new registrations. 720 o Allowing attachment of comments to the registration. This can be 721 useful in cases where others have significant objections to a 722 registration, but the author does not agree to change the 723 registration. 725 o Designating the IESG, a designated expert, or another entity as 726 having the right to change the registrant associated with a 727 registration and any requirements or conditions on doing so. This 728 is mainly to get around the problem when a registrant cannot be 729 reached in order to make necessary updates. 731 3.3. Overriding Registration Procedures 733 Experience has shown that the documented IANA considerations for 734 individual protocols do not always adequately cover the reality of 735 registry operation, or are not sufficiently clear. In addition, 736 documented IANA considerations are sometimes found to be too 737 stringent to allow even working group documents (for which there is 738 strong consensus) to perform a registration in advance of actual RFC 739 publication. 741 In order to allow assignments in such cases, the IESG is granted 742 authority to override registration procedures and approve assignments 743 on a case-by-case basis. 745 The intention here is not to overrule properly documented procedures, 746 or to obviate the need for protocols to properly document their IANA 747 considerations. Rather, it is to permit assignments in specific 748 cases where it is obvious that the assignment should just be made, 749 but updating the IANA process beforehand is too onerous. 751 When the IESG is required to take action as described in this 752 section, it is a strong indicator that the applicable registration 753 procedures should be updated, possibly in parallel with the work that 754 instigated it. 756 3.4. Early Allocations 758 IANA normally takes its actions when a document is approved for 759 publication. There are times, though, when early allocation of a 760 value is important for the development of a technology: for example, 761 when early implementations are created while the document is still 762 under development. 764 IANA has a mechanism for handling such early allocations in some 765 cases. See [RFC7120] for details. 767 4. Well-Known Registration Policies 768 The following are some defined policies, most of which are in use 769 today. These cover a range of typical policies that have been used 770 to describe the procedure for assigning new values in a namespace. 771 It is not strictly required that documents use these terms; the 772 actual requirement is that the instructions to IANA be clear and 773 unambiguous. However, use of these terms is strongly RECOMMENDED, 774 because their meanings are widely understood. The terms are fully 775 explained in the following subsections. 777 1. Private Use 778 2. Experimental Use 779 3. Hierarchical Allocation 780 4. First Come First Served 781 5. Expert Review 782 6. Specification Required 783 7. RFC Required 784 8. IETF Review 785 9. Standards Action 786 10. IESG Approval 788 It should be noted that it often makes sense to partition a namespace 789 into multiple categories, with assignments within each category 790 handled differently. Many protocols now partition namespaces into 791 two or more parts, with one range reserved for Private or 792 Experimental Use while other ranges are reserved for globally unique 793 assignments assigned following some review process. Dividing a 794 namespace into ranges makes it possible to have different policies in 795 place for different ranges and different use cases. 797 Similarly, it will often be useful to specify multiple policies in 798 parallel, with each policy being used under different circumstances. 799 For more discussion of that topic, see Section 2.3.2. 801 Examples: 803 LDAP [RFC4520] 804 TLS ClientCertificateType Identifiers [RFC5246] (as detailed in 805 the subsections below) 806 Pseudowire Edge to Edge Emulation (PWE3) [RFC4446] 808 4.1. Private Use 810 For private or local use only, with the type and purpose defined by 811 the local site. No attempt is made to prevent multiple sites from 812 using the same value in different (and incompatible) ways. There is 813 no need for IANA to review such assignments (since IANA does not 814 record them) and assignments are not generally useful for broad 815 interoperability. It is the responsibility of the sites making use 816 of the Private Use range to ensure that no conflicts occur (within 817 the intended scope of use). 819 Examples: 821 Site-specific options in DHCP [RFC2939] 822 Fibre Channel Port Type Registry [RFC4044] 823 TLS ClientCertificateType Identifiers 224-255 [RFC5246] 825 4.2. Experimental Use 827 Experimental Use is similar to Private Use only, but with the purpose 828 being to facilitate experimentation. See [RFC3692] for details. 830 Example: 832 Experimental Values in IPv4, IPv6, ICMPv4, ICMPv6, UDP, and TCP 833 Headers [RFC4727] 835 4.3. Hierarchical Allocation 837 With Hierarchical Allocation, delegated administrators are given 838 control over part of the namespace, and can assign values in that 839 part of the namespace. IANA makes allocations in the higher levels 840 of the namespace according to one of the other policies. 842 Examples: 844 DNS names 845 Object Identifiers 846 IP addresses 848 4.4. First Come First Served 850 For the First Come First Served policy, assignments are made to 851 anyone on a first come, first served basis. There is no substantive 852 review of the request, other than to ensure that it is well-formed 853 and doesn't duplicate an existing assignment. However, requests must 854 include a minimal amount of clerical information, such as a point of 855 contact (including an email address, and sometimes a postal address) 856 and a brief description of how the value will be used. Additional 857 information specific to the type of value requested may also need to 858 be provided, as defined by the namespace. For numbers, the exact 859 value is generally assigned by IANA; with names, specific text 860 strings can usually be requested. 862 Examples: 864 SASL mechanism names [RFC4422] 865 LDAP Protocol Mechanisms and LDAP Syntax [RFC4520] 867 4.5. Expert Review 868 (Also called "Designated Expert" in earlier editions of this 869 document.) For the Expert Review policy, review and approval by a 870 designated expert (see Section 5) is required. The required 871 documentation and review criteria for use by the designated expert 872 should be provided when defining the registry. For example, see 873 Sections 6 and 7.2 in [RFC3748]. 875 It is particularly important, when using a designated expert, to give 876 clear guidance to the expert, laying out criteria for performing an 877 evaluation and reasons for rejecting a request. When specifying a 878 policy that involves a designated expert, the IANA Considerations 879 SHOULD contain such guidance. It is also a good idea to include, 880 when possible, a sense of whether many registrations are expected 881 over time, or if the registry is expected to be updated infrequently 882 or in exceptional circumstances only. 884 Examples: 886 EAP Method Types [RFC3748] 887 HTTP Digest AKA algorithm versions [RFC4169] 888 URI schemes [RFC4395] 889 GEOPRIV Location Types [RFC4589] 891 4.6. Specification Required 893 For the Specification Required policy, review and approval by a 894 designated expert (see Section 5) is required, and the values and 895 their meanings must be documented in a permanent and readily 896 available public specification, in sufficient detail so that 897 interoperability between independent implementations is possible. 898 The designated expert will review the public specification and 899 evaluate whether it is sufficiently clear to allow interoperable 900 implementations. The intention behind "permanent and readily 901 available" is that a document can reasonably be expected to be 902 findable and retrievable long after IANA assignment of the requested 903 value. Publication of an RFC is an ideal means of achieving this 904 requirement, but Specification Required is intended to also cover the 905 case of a document published outside of the RFC path. For RFC 906 publication, the normal RFC review process is expected to provide the 907 necessary review for interoperability, though the designated expert 908 may be a particularly well-qualified person to perform such a review. 910 When specifying this policy, just use the term "Specification 911 Required". Some specifications have chosen to refer to it as "Expert 912 Review with Specification Required", and that only causes confusion. 914 Examples: 916 Diffserv-aware TE Bandwidth Constraints Model Identifiers 918 [RFC4124] 919 TLS ClientCertificateType Identifiers 64-223 [RFC5246] 920 ROHC Profile Identifiers [RFC5795] 922 4.7. RFC Required 924 With the RFC Required policy, the registration request, along with 925 associated documentation, must be published in an RFC. The RFC need 926 not be in the IETF stream, but may be in any RFC stream (currently an 927 RFC may be in the IETF, IRTF, or IAB stream, or an RFC Editor 928 Independent Submission [RFC5742]). Unless otherwise specified, any 929 type of RFC is sufficient (currently Standards Track, BCP, 930 Informational, Experimental, or Historic). 932 4.8. IETF Review 934 (Formerly called "IETF Consensus" in the first edition of this 935 document.) With the IETF Review policy, new values are assigned only 936 through RFCs in the IETF Stream -- those that have been shepherded 937 through the IESG as AD-Sponsored or IETF working group Documents 938 [RFC2026] [RFC5378]. 940 The intent is that the document and proposed assignment will be 941 reviewed by the IETF community (including appropriate IETF working 942 groups, directorates, and other experts) and by the IESG, to ensure 943 that the proposed assignment will not negatively affect 944 interoperability or otherwise extend IETF protocols in an 945 inappropriate or damaging manner. To ensure adequate community 946 review, such documents will always undergo an IETF Last Call. 948 Examples: 950 IPSECKEY Algorithm Types [RFC4025] 951 Accounting-Auth-Method AVP values in DIAMETER [RFC4005] 952 TLS Extension Types [RFC5246] 954 4.9. Standards Action 956 For the Standards Action policy, values are assigned only through 957 Standards Track RFCs approved by the IESG. 959 Examples: 961 BGP message types [RFC4271] 962 Mobile Node Identifier option types [RFC4283] 963 TLS ClientCertificateType Identifiers 0-63 [RFC5246] 964 DCCP Packet Types [RFC4340] 966 4.10. IESG Approval 968 New assignments may be approved by the IESG. Although there is no 969 requirement that the request be documented in an RFC, the IESG has 970 discretion to request documents or other supporting materials on a 971 case-by-case basis. 973 IESG Approval is not intended to be used often or as a "common case"; 974 indeed, it has seldom been used in practice during the period RFC 975 2434 was in effect. Rather, it is intended to be available in 976 conjunction with other policies as a fall-back mechanism in the case 977 where one of the other allowable approval mechanisms cannot be 978 employed in a timely fashion or for some other compelling reason. 979 IESG Approval is not intended to circumvent the public review 980 processes implied by other policies that could have been employed for 981 a particular assignment. IESG Approval would be appropriate, 982 however, in cases where expediency is desired and there is strong 983 consensus (such as from a working group) for making the assignment. 985 The following guidelines are suggested for any evaluation under IESG 986 Approval: 988 o The IESG can (and should) reject a request if another path for 989 registration is available that is more appropriate and there is no 990 compelling reason not to use that path. 992 o Before approving a request, the community should be consulted, via 993 a "call for comments" that provides as much information as is 994 reasonably possible about the request. 996 Examples: 998 IPv4 Multicast address assignments [RFC5771] 999 IPv4 IGMP Type and Code values [RFC3228] 1000 Mobile IPv6 Mobility Header Type and Option values [RFC6275] 1002 5. Designated Experts 1004 5.1. The Motivation for Designated Experts 1006 IANA does not define registry policy itself; rather, it carries out 1007 policies that have been defined by others and published in RFCs. As 1008 part of that process, review of proposed registrations is often 1009 appropriate. 1011 A common way to ensure such review is for a proposed registration to 1012 be published as an RFC, as this ensures that the specification is 1013 publicly and permanently available. It is particularly important if 1014 any potential interoperability issues might arise. For example, some 1015 assignments are not just assignments, but also involve an element of 1016 protocol specification. A new option may define fields that need to 1017 be parsed and acted on, which (if specified poorly) may not fit 1018 cleanly with the architecture of other options or the base protocols 1019 on which they are built. 1021 In some cases, however, the burden of publishing an RFC in order to 1022 register a protocol element is excessive. 1024 However, it is generally still useful (and sometimes necessary) to 1025 discuss proposed registrations within the community, on a mailing 1026 list. Such a mailing list provides opportunity for public review 1027 prior to assignment, and allows for a consultative process when 1028 registrants want help in understanding what a proper registration 1029 should contain. 1031 While discussion on a mailing list can provide valuable technical 1032 feedback, opinions may vary and discussions may continue for some 1033 time without clear resolution. In addition, IANA cannot participate 1034 in all of these mailing lists and cannot determine if or when such 1035 discussions reach consensus. Therefore, IANA relies on a "designated 1036 expert" for advice regarding the specific question of whether an 1037 assignment should be made. The designated expert is an individual 1038 who is responsible for carrying out an appropriate evaluation and 1039 returning a recommendation to IANA. 1041 It should be noted that a key motivation for having designated 1042 experts is for the IETF to provide IANA with a subject matter expert 1043 to whom the evaluation process can be delegated. IANA forwards 1044 requests for an assignment to the expert for evaluation, and the 1045 expert (after performing the evaluation) informs IANA as to whether 1046 or not to make the assignment or registration. 1048 It will often be useful to use a designated expert only some of the 1049 time, as a supplement to other processes. For more discussion of 1050 that topic, see Section 2.3.2. 1052 5.2. The Role of the Designated Expert 1054 The designated expert is responsible for coordinating the appropriate 1055 review of an assignment request. The review may be wide or narrow, 1056 depending on the situation and the judgment of the designated expert. 1057 This may involve consultation with a set of technology experts, 1058 discussion on a public mailing list, consultation with a working 1059 group (or its mailing list if the working group has disbanded), etc. 1060 Ideally, the designated expert follows specific review criteria as 1061 documented with the protocol that creates or uses the namespace. See 1062 the IANA Considerations sections of [RFC3748] and [RFC3575] for 1063 specific examples. 1065 Designated experts are expected to be able to defend their decisions 1066 to the IETF community, and the evaluation process is not intended to 1067 be secretive or bestow unquestioned power on the expert. Experts are 1068 expected to apply applicable documented review or vetting procedures, 1069 or in the absence of documented criteria, follow generally accepted 1070 norms such as those in Section 5.3. 1072 Designated experts are appointed by the IESG, normally upon 1073 recommendation by the relevant Area Director, either at the time a 1074 document creating or updating a namespace is approved by the IESG or 1075 subsequently, when the first registration request is received. 1076 Because experts originally appointed may later become unavailable, 1077 the IESG will appoint replacements as necessary. 1079 For some registries, it has proven useful to have multiple designated 1080 experts. Sometimes those experts work together in evaluating a 1081 request, while in other cases additional experts serve as backups. 1082 In cases of disagreement among those experts, it is the 1083 responsibility of those experts to make a single clear recommendation 1084 to IANA. It is not appropriate for IANA to resolve disputes among 1085 experts. In extreme situations, such as deadlock, the IESG may need 1086 to step in to resolve the problem. 1088 In registries where a pool of experts evaluates requests, the pool 1089 should have a single chair responsible for defining how requests are 1090 to be assigned to and reviewed by experts. In some cases, the expert 1091 pool may consist of a primary and backups, with the backups involved 1092 only when the primary expert is unavailable. In other cases, IANA 1093 might assign requests to individual members in sequential or 1094 approximate random order. In the event that IANA finds itself having 1095 received conflicting advice from its experts, it is the 1096 responsibility of the pool's chair to resolve the issue and provide 1097 IANA with clear instructions. 1099 If a designated expert is conflicted for a particular review (is, for 1100 example, an author or significant proponent of a specification 1101 related to the registration under review), that expert should recuse 1102 himself. In the event that all the designated experts are 1103 conflicted, they should ask the IESG to designate a temporary expert 1104 for the conflicted review. 1106 As the designated experts are appointed by the IESG, they may be 1107 removed by the IESG. 1109 5.3. Designated Expert Reviews 1111 In the years since RFC 2434 was published and has been put to use, 1112 experience has led to the following observations: 1114 o A designated expert must respond in a timely fashion, normally 1115 within a week for simple requests to a few weeks for more complex 1116 ones. Unreasonable delays can cause significant problems for 1117 those needing assignments, such as when products need code points 1118 to ship. This is not to say that all reviews can be completed 1119 under a firm deadline, but they must be started, and the requester 1120 and IANA should have some transparency into the process if an 1121 answer cannot be given quickly. 1123 o If a designated expert does not respond to IANA's requests within 1124 a reasonable period of time, either with a response or with a 1125 reasonable explanation for the delay (some requests may be 1126 particularly complex), and if this is a recurring event, IANA must 1127 raise the issue with the IESG. Because of the problems caused by 1128 delayed evaluations and assignments, the IESG should take 1129 appropriate actions to ensure that the expert understands and 1130 accepts his or her responsibilities, or appoint a new expert. 1132 o The designated expert is not required to personally bear the 1133 burden of evaluating and deciding all requests, but acts as a 1134 shepherd for the request, enlisting the help of others as 1135 appropriate. In the case that a request is denied, and rejecting 1136 the request is likely to be controversial, the expert should have 1137 the support of other subject matter experts. That is, the expert 1138 must be able to defend a decision to the community as a whole. 1140 When a designated expert is used, the documentation should give clear 1141 guidance to the designated expert, laying out criteria for performing 1142 an evaluation and reasons for rejecting a request. In the case where 1143 there are no specific documented criteria, the presumption should be 1144 that a code point should be granted unless there is a compelling 1145 reason to the contrary. Possible reasons to deny a request include 1146 these: 1148 o Scarcity of code points, where the finite remaining code points 1149 should be prudently managed, or when a request for a large number 1150 of code points is made, when a single code point is the norm. 1152 o Documentation is not of sufficient clarity to evaluate or ensure 1153 interoperability. 1155 o The code point is needed for a protocol extension, but the 1156 extension is not consistent with the documented (or generally 1157 understood) architecture of the base protocol being extended, and 1158 would be harmful to the protocol if widely deployed. It is not 1159 the intent that "inconsistencies" refer to minor differences "of a 1160 personal preference nature". Instead, they refer to significant 1161 differences such as inconsistencies with the underlying security 1162 model, implying a change to the semantics of an existing message 1163 type or operation, requiring unwarranted changes in deployed 1164 systems (compared with alternate ways of achieving a similar 1165 result), etc. 1167 o The extension would cause problems with existing deployed systems. 1169 o The extension would conflict with one under active development by 1170 the IETF, and having both would harm rather than foster 1171 interoperability. 1173 When a designated expert is used, documents MUST NOT name the 1174 designated expert in the document itself; instead, any suggested 1175 names should be relayed to the appropriate Area Director at the time 1176 the document is sent to the IESG for approval. This is usually done 1177 in the document shepherd writeup. 1179 If the request should also be reviewed on a specific public mailing 1180 list, its address should be specified. 1182 5.4. Expert Reviews and the Document Lifecycle 1184 Review by the designated expert is necessarily done at a particular 1185 point in time, and represents review of a particular version of the 1186 document. Deciding when the review should take place is a question 1187 of good judgment. And while re-reviews might be done when it's 1188 acknowledged that the documentation of the registered item has 1189 changed substantially, making sure that re-review happens requires 1190 attention and care. 1192 It is possible, through carelessness, accident, inattentiveness, or 1193 even willful disregard, that changes might be made after the 1194 designated expert's review and approval that would, if the document 1195 were re-reviewed, cause the expert not to approve the registration. 1196 It is up to the IESG, with the token held by the responsible Area 1197 Director, to be alert to such situations and to recognize that such 1198 changes need to be checked. 1200 6. Well-Known Registration Status Terminology 1202 The following labels describe the status of an assignment or range of 1203 assignments: 1205 Private Use: Private use only (not assigned), as described in 1206 Section 4.1. 1208 Experimental: Available for general experimental use as described 1209 in [RFC3692]. IANA does not record specific assignments for 1210 any particular use. 1212 Unassigned: Not currently assigned, and available for assignment 1213 via documented procedures. While it's generally clear that 1214 any values that are not registered are unassigned and 1215 available for assignment, it is sometimes useful to 1216 explicitly specify that situation. Note that this is 1217 distinctly different from "Reserved". 1219 Reserved: Not assigned and not available for assignment. Reserved 1220 values are held for special uses, such as to extend the 1221 namespace when it becomes exhausted. Note that this is 1222 distinctly different from "Unassigned". 1224 Reserved values can be released for assignment by the change 1225 controller for the registry (this is often the IESG, for 1226 registries created by RFCs in the IETF stream). 1228 7. Documentation References in IANA Registries 1230 Usually, registries and registry entries include references to 1231 documentation (RFCs or other documents). The purpose of these 1232 references is to provide pointers for implementors to find details 1233 necessary for implementation, NOT to simply note what document 1234 created the registry or entry. Therefore: 1236 o If a document registers an item that is defined and explained 1237 elsewhere, the registered reference should be to that document, 1238 and not to the document that is merely performing the 1239 registration. 1241 o If the registered item is defined and explained in the current 1242 document, it is important to include sufficient information to 1243 enable implementors to understand the item and to create a proper 1244 implementation. 1246 o If the registered item is explained primarily in a specific 1247 section of the reference document, it is useful to include a 1248 section reference. For example, "[RFC9876], Section 3.2", rather 1249 than just "[RFC9876]". 1251 o For documentation of a new registry, the reference should provide 1252 information about the registry itself, not just a pointer to the 1253 creation of it. Useful information includes the purpose of the 1254 registry, a rationale for its creation, documentation of the 1255 process and policy for new registrations, guidelines for new 1256 registrants or designated experts, and other such related 1257 information. But note that, while it's important to include this 1258 information in the document, it needn't (and shouldn't) all be in 1259 the IANA Considerations section. See Section 1.1. 1261 8. What to Do in "bis" Documents 1263 On occaison, an RFC is issued that obsoletes a previous edition of 1264 the same document. We sometimes call these "bis" documents, such as 1265 when RFC 9876 is updated by draft-ietf-foo-rfc9876bis. When the 1266 original document created registries and/or registered entries, there 1267 is a question of how to handle the IANA Considerations section in the 1268 "bis" document. 1270 If the registrations specify the original document as a reference, 1271 those registrations should be updated to point to the current (not 1272 obsolete) documentation for those items. Usually, that will mean 1273 changing the reference to be the "bis" document. There will, though, 1274 be times when a document updates another, and changes the definitive 1275 reference for some items, but not for others. Be sure that the 1276 references are always set to point to the correct, current 1277 documentation for each item. 1279 For example, suppose RFC 9876 registered the "BANANA" flag in the 1280 "Fruit Access Flags" registry, and the documentation for that flag is 1281 in Section 3.2. 1283 The current registry might look, in part, like this: 1285 Name Description Reference 1286 -------- ------------------- --------- 1287 BANANA Flag for bananas [RFC9876], Section 3.2 1289 If draft-ietf-foo-rfc9876bis obsoletes RFC 9876 and, because of some 1290 rearrangement, now documents the flag in Section 4.1.2, the IANA 1291 Considerations of the bis document might contain text such as this: 1293 IANA is asked to change the registration information for the 1294 BANANA flag in the "Fruit Access Flags" registry to the following: 1296 Name Description Reference 1297 -------- ------------------- --------- 1298 BANANA Flag for bananas [[this RFC]], Section 4.2.1 1300 In many cases, if there are a number of registered references to the 1301 original RFC and the document organization has not changed the 1302 registered section numbering much, it may simply be reasonable to do 1303 this: 1305 Because this document obsoletes RFC 9876, IANA is asked to change 1306 all registration information that references [RFC9876] to instead 1307 reference [[this RFC]]. 1309 If information for registered items has been or is being moved to 1310 other documents, then, of course, the registration information should 1311 be changed to point to those other documents. In no case is it 1312 reasonable to leave documentation pointers to the obsoleted document 1313 for any registries or registered items that are still in current use. 1315 It is extremely important to be clear in your instructions regarding 1316 updating references, especially in cases where some references need 1317 to be updated and others do not. 1319 9. Miscellaneous Issues 1321 9.1. When There Are No IANA Actions 1323 Before an Internet-Draft can be published as an RFC, IANA needs to 1324 know what actions (if any) it needs to perform. Experience has shown 1325 that it is not always immediately obvious whether a document has no 1326 IANA actions, without reviewing the document in some detail. In 1327 order to make it clear to IANA that it has no actions to perform (and 1328 that the author has consciously made such a determination), such 1329 documents should include an IANA Considerations section that states: 1331 This document has no IANA actions. 1333 This statement, or an equivalent, must only be inserted after the 1334 working group or individual submitter has carefully verified it to be 1335 true. Using such wording as a matter of "boilerplate" or without 1336 careful consideration can lead to incomplete or incorrect IANA 1337 actions being performed. 1339 If a specification makes use of values from a namespace in which 1340 assignments are not made by IANA, it may be useful to note this fact, 1341 with wording such as this: 1343 The values of the Foobar parameter are assigned by the Barfoo 1344 registry on behalf of the Rabfoo Forum. Therefore, this document 1345 has no IANA actions. 1347 In some cases, the absence of IANA-assigned values may be considered 1348 valuable information for future readers; in other cases, it may be 1349 considered of no value once the document has been approved, and may 1350 be removed before archival publication. This choice should be made 1351 clear in the draft, for example, by including a sentence such as 1353 [RFC Editor: please remove this section prior to publication.] 1355 or 1357 [RFC Editor: please do not remove this section.] 1359 9.2. Namespaces Lacking Documented Guidance 1361 For all existing RFCs that either explicitly or implicitly rely on 1362 IANA to make assignments without specifying a precise assignment 1363 policy, IANA (in consultation with the IESG) will continue to decide 1364 what policy is appropriate. Changes to existing policies can always 1365 be initiated through the normal IETF consensus process, or through 1366 the IESG when appropriate. 1368 All future RFCs that either explicitly or implicitly rely on IANA to 1369 register or otherwise administer namespace assignments MUST provide 1370 guidelines for administration of the namespace. 1372 9.3. After-the-Fact Registrations 1373 Occasionally, the IETF becomes aware that an unassigned value from a 1374 namespace is in use on the Internet or that an assigned value is 1375 being used for a different purpose than it was registered for. The 1376 IETF does not condone such misuse; procedures of the type described 1377 in this document MUST be applied to such cases. In the absence of 1378 specifications to the contrary, values may only be reassigned for a 1379 different purpose with the consent of the original assignee (when 1380 possible) and with due consideration of the impact of such a 1381 reassignment. In cases of likely controversy, consultation with the 1382 IESG is advised. 1384 9.4. Reclaiming Assigned Values 1386 Reclaiming previously assigned values for reuse is tricky, because 1387 doing so can lead to interoperability problems with deployed systems 1388 still using the assigned values. Moreover, it can be extremely 1389 difficult to determine the extent of deployment of systems making use 1390 of a particular value. However, in cases where the namespace is 1391 running out of unassigned values and additional ones are needed, it 1392 may be desirable to attempt to reclaim unused values. When 1393 reclaiming unused values, the following (at a minimum) should be 1394 considered: 1396 o Attempts should be made to contact the original party to which a 1397 value is assigned, to determine if the value was ever used, and if 1398 so, the extent of deployment. (In some cases, products were never 1399 shipped or have long ceased being used. In other cases, it may be 1400 known that a value was never actually used at all.) 1402 o Reassignments should not normally be made without the concurrence 1403 of the original requester. Reclamation under such conditions 1404 should only take place where there is strong evidence that a value 1405 is not widely used, and the need to reclaim the value outweighs 1406 the cost of a hostile reclamation. In any case, IESG Approval is 1407 needed in this case. 1409 o It may be appropriate to write up the proposed action and solicit 1410 comments from relevant user communities. In some cases, it may be 1411 appropriate to write an RFC that goes through a formal IETF 1412 process (including IETF Last Call) as was done when DHCP reclaimed 1413 some of its "Private Use" options [RFC3942]. 1415 9.5. Contact Person vs Assignee or Owner 1417 Many registries include designation of a technical or administrative 1418 contact associated with each entry. Often, this is recorded as 1419 contact information for an individual. It is unclear, though, what 1420 role the individual has with respect to the registration: is this 1421 item registered on behalf of the individual, the company the 1422 individual worked for, or perhaps another organization the individual 1423 was acting for? 1424 This matters because some time later, when the individual has changed 1425 jobs or roles, and perhaps can no longer be contacted, someone might 1426 want to update the registration. IANA has no way to know what 1427 company, organization, or individual should be allowed to take the 1428 registration over. For registrations rooted in RFCs, the stream 1429 owner (such as the IESG or the IAB) can make an overriding decision. 1430 But in other cases, there is no recourse. 1432 Registries can include, in addition to a "Contact" field, an 1433 "Assignee" or "Owner" field that can be used to address this 1434 situation, giving IANA clear guidance as to the actual owner of the 1435 registration. This is strongly advised especially for registries 1436 that do not require RFCs to manage their information (registries with 1437 policies such as First Come First Served Section 4.4, Expert Review 1438 Section 4.5, and Specification Required Section 4.6). Alternatively, 1439 organizations can put an organizational role into the "Contact" field 1440 in order to make their ownership clear. 1442 9.6. Closing or Obsoleting a Registry 1444 Sometimes there is a request to "close" a registry to further 1445 registrations. When a registry is closed, no further registrations 1446 will be accepted. The information in the registry will still be 1447 valid and registrations already in the registry can still be updated. 1449 A closed registry can also be marked as "obsolete", as an indication 1450 that the information in the registry is no longer in current use. 1452 Specific entries in a registry can be marked as "obsolete" (no longer 1453 in use) or "deprecated" (use is not recommended). 1455 Such changes to registries and registered values are subject to 1456 normal change controls (see Section 2.3.3). Any closure, 1457 obsolescence, or deprecation serves to annotate the registry 1458 involved; the information in the registry remains there for 1459 informational and historic purposes. 1461 10. Appeals 1463 Appeals of protocol parameter registration decisions can be made 1464 using the normal IETF appeals process as described in [RFC2026], 1465 Section 6.5. That is, an initial appeal should be directed to the 1466 IESG, followed (if necessary) by an appeal to the IAB. 1468 11. Mailing Lists 1470 All IETF mailing lists associated with evaluating or discussing 1471 assignment requests as described in this document are subject to 1472 whatever rules of conduct and methods of list management are 1473 currently defined by Best Current Practices or by IESG decision. 1475 12. Security Considerations 1476 Information that creates or updates a registration needs to be 1477 authenticated and authorized. IANA updates registries according to 1478 instructions in published RFCs and from the IESG. It also may accept 1479 clarifications from document authors, relevant working group chairs, 1480 Designated Experts, and mail list participants, too. 1482 Information concerning possible security vulnerabilities of a 1483 protocol may change over time. Likewise, security vulnerabilities 1484 related to how an assigned number is used may change as well. As new 1485 vulnerabilities are discovered, information about such 1486 vulnerabilities may need to be attached to existing registrations, so 1487 that users are not misled as to the true security issues surrounding 1488 the use of a registered number. 1490 An analysis of security issues is generally required for all 1491 protocols that make use of parameters (data types, operation codes, 1492 keywords, etc.) used in IETF protocols or registered by IANA. Such 1493 security considerations are usually included in the protocol document 1494 [RFC3552]. It is the responsibility of the IANA considerations 1495 associated with a particular registry to specify what (if any) 1496 security considerations must be provided when assigning new values, 1497 and the process for reviewing such claims. 1499 13. Changes Relative to Earlier Editions of BCP 26 1501 13.1. 2014: Changes in This Document Relative to RFC 5226 1503 Significant additions: 1505 o Added Section 1.1, Keep IANA Considerations for IANA 1507 o Added Section 1.2, For More Information 1509 o Added Section 2.1, Hierarchical Registry Structure 1511 o Added Section 2.3, Best Practice for Selecting an Appropriate 1512 Policy. 1514 o Added Section 2.3.2, Using Multiple Policies in Combination. 1516 o Added Section 2.3.3, Specifying Change Control for a Registry 1518 o Added Section 3.4, Early Allocations 1520 o Moved well-known policies into a separate section for each, 1521 subsections of Section 4. 1523 o Added Section 5.4, Expert Reviews and the Document Lifecycle 1525 o Added Section 7, Documentation References in IANA Registries 1527 o Added Section 8, What to Do in "bis" Documents 1528 o Added Section 9.5, Contact Person vs Assignee or Owner 1530 o Added Section 9.6, Closing or Obsoleting a Registry 1532 Clarifications and such: 1534 o Some reorganization -- moved text around for clarity and easier 1535 reading. 1537 o Made clarifications about identification of IANA registries and 1538 use of URLs for them. 1540 o Clarified the distinction between "Unassigned" and "Reserved". 1542 o Made some clarifications in "Expert Review" about instructions to 1543 the designated expert. 1545 o Made some clarifications in "Specification Required" about how to 1546 declare this policy. 1548 o Assorted minor clarifications and editorial changes throughout. 1550 13.2. 2008: Changes in RFC 5226 Relative to RFC 2434 1552 Changes include: 1554 o Major reordering of text to expand descriptions and to better 1555 group topics such as "updating registries" vs. "creating new 1556 registries", in order to make it easier for authors to find the 1557 text most applicable to their needs. 1559 o Numerous editorial changes to improve readability. 1561 o Changed the term "IETF Consensus" to "IETF Review" and added more 1562 clarifications. History has shown that people see the words "IETF 1563 Consensus" (without consulting the actual definition) and are 1564 quick to make incorrect assumptions about what the term means in 1565 the context of IANA Considerations. 1567 o Added "RFC Required" to list of defined policies. 1569 o Much more explicit directions and examples of "what to put in 1570 RFCs". 1572 o "Specification Required" now implies use of a Designated Expert to 1573 evaluate specs for sufficient clarity. 1575 o Significantly changed the wording in the Designated Experts 1576 section. Main purpose is to make clear that Expert Reviewers are 1577 accountable to the community, and to provide some guidance for 1578 review criteria in the default case. 1580 o Changed wording to remove any special appeals path. The normal 1581 RFC 2026 appeals path is used. 1583 o Added a section about reclaiming unused value. 1585 o Added a section on after-the-fact registrations. 1587 o Added a section indicating that mailing lists used to evaluate 1588 possible assignments (such as by a Designated Expert) are subject 1589 to normal IETF rules. 1591 14. Acknowledgments 1593 14.1. Acknowledgments for This Document (2014) 1595 Thomas Narten and Harald Tveit Alvestrand edited the two earlier 1596 editions of this document (RFCs 2434 and 5226), and Thomas continues 1597 his role in this third edition. Much of the text from RFC 5226 1598 remains in this edition. 1600 Thank you to Amanda Baber and Pearl Liang for their multiple reviews 1601 and suggestions for making this document as thorough as possible. 1603 This document has benefited from thorough review and comments by John 1604 Klensin and Mark Nottingham. 1606 Special thanks to Mark Nottingham for reorganizing some of the text 1607 for better organization and readability. 1609 14.2. Acknowledgments from the second edition (2008) 1611 The original acknowledgments section in RFC 5226 was: 1613 This document has benefited from specific feedback from Jari Arkko, 1614 Marcelo Bagnulo Braun, Brian Carpenter, Michelle Cotton, Spencer 1615 Dawkins, Barbara Denny, Miguel Garcia, Paul Hoffman, Russ Housley, 1616 John Klensin, Allison Mankin, Blake Ramsdell, Mark Townsley, Magnus 1617 Westerlund, and Bert Wijnen. 1619 14.3. Acknowledgments from the first edition (1998) 1621 The original acknowledgments section in RFC 2434 was: 1623 Jon Postel and Joyce Reynolds provided a detailed explanation on what 1624 IANA needs in order to manage assignments efficiently, and patiently 1625 provided comments on multiple versions of this document. Brian 1626 Carpenter provided helpful comments on earlier versions of the 1627 document. One paragraph in the Security Considerations section was 1628 borrowed from [RFC4288]. 1630 15. References 1632 15.1. Normative References 1634 [RFC2026] Bradner, S., "The Internet Standards Process -- Revision 1635 3", BCP 9, RFC 2026, October 1996. 1637 [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate 1638 Requirement Levels", BCP 14, RFC 2119, March 1997. 1640 15.2. Informative References 1642 [RFC0791] Postel, J., "Internet Protocol", STD 5, RFC 791, September 1643 1981. 1645 [RFC2860] Carpenter, B., Baker, F. and M. Roberts, "Memorandum of 1646 Understanding Concerning the Technical Work of the 1647 Internet Assigned Numbers Authority", RFC 2860, June 2000. 1649 [RFC2939] Droms, R., "Procedures and IANA Guidelines for Definition 1650 of New DHCP Options and Message Types", BCP 43, RFC 2939, 1651 September 2000. 1653 [RFC3228] Fenner, B., "IANA Considerations for IPv4 Internet Group 1654 Management Protocol (IGMP)", BCP 57, RFC 3228, February 1655 2002. 1657 [RFC3552] Rescorla, E. and B. Korver, "Guidelines for Writing RFC 1658 Text on Security Considerations", BCP 72, RFC 3552, July 1659 2003. 1661 [RFC3575] Aboba, B., "IANA Considerations for RADIUS (Remote 1662 Authentication Dial In User Service)", RFC 3575, July 1663 2003. 1665 [RFC3692] Narten, T., "Assigning Experimental and Testing Numbers 1666 Considered Useful", BCP 82, RFC 3692, January 2004. 1668 [RFC3748] Aboba, B., Blunk, L., Vollbrecht, J., Carlson, J. and H. 1669 Levkowetz, "Extensible Authentication Protocol (EAP)", RFC 1670 3748, June 2004. 1672 [RFC3942] Volz, B., "Reclassifying Dynamic Host Configuration 1673 Protocol version 4 (DHCPv4) Options", RFC 3942, November 1674 2004. 1676 [RFC3968] Camarillo, G., "The Internet Assigned Number Authority 1677 (IANA) Header Field Parameter Registry for the Session 1678 Initiation Protocol (SIP)", BCP 98, RFC 3968, December 1679 2004. 1681 [RFC4005] Calhoun, P., Zorn, G., Spence, D. and D. Mitton, "Diameter 1682 Network Access Server Application", RFC 4005, August 2005. 1684 [RFC4025] Richardson, M., "A Method for Storing IPsec Keying 1685 Material in DNS", RFC 4025, March 2005. 1687 [RFC4044] McCloghrie, K., "Fibre Channel Management MIB", RFC 4044, 1688 May 2005. 1690 [RFC4124] Le Faucheur, F., "Protocol Extensions for Support of 1691 Diffserv-aware MPLS Traffic Engineering", RFC 4124, June 1692 2005. 1694 [RFC4169] Torvinen, V., Arkko, J. and M. Naslund, "Hypertext 1695 Transfer Protocol (HTTP) Digest Authentication Using 1696 Authentication and Key Agreement (AKA) Version-2", RFC 1697 4169, November 2005. 1699 [RFC4271] Rekhter, Y., Li, T. and S. Hares, "A Border Gateway 1700 Protocol 4 (BGP-4)", RFC 4271, January 2006. 1702 [RFC4283] Patel, A., Leung, K., Khalil, M., Akhtar, H. and K. 1703 Chowdhury, "Mobile Node Identifier Option for Mobile IPv6 1704 (MIPv6)", RFC 4283, November 2005. 1706 [RFC4288] Freed, N. and J. Klensin, "Media Type Specifications and 1707 Registration Procedures", BCP 13, RFC 4288, December 2005. 1709 [RFC4340] Kohler, E., Handley, M. and S. Floyd, "Datagram Congestion 1710 Control Protocol (DCCP)", RFC 4340, March 2006. 1712 [RFC4395] Hansen, T., Hardie, T. and L. Masinter, "Guidelines and 1713 Registration Procedures for New URI Schemes", BCP 35, RFC 1714 4395, February 2006. 1716 [RFC4422] Melnikov, A. and K. Zeilenga, "Simple Authentication and 1717 Security Layer (SASL)", RFC 4422, June 2006. 1719 [RFC4446] Martini, L., "IANA Allocations for Pseudowire Edge to Edge 1720 Emulation (PWE3)", BCP 116, RFC 4446, April 2006. 1722 [RFC4520] Zeilenga, K., "Internet Assigned Numbers Authority (IANA) 1723 Considerations for the Lightweight Directory Access 1724 Protocol (LDAP)", BCP 64, RFC 4520, June 2006. 1726 [RFC4589] Schulzrinne, H. and H. Tschofenig, "Location Types 1727 Registry", RFC 4589, July 2006. 1729 [RFC4727] Fenner, B., "Experimental Values In IPv4, IPv6, ICMPv4, 1730 ICMPv6, UDP, and TCP Headers", RFC 4727, November 2006. 1732 [RFC5246] Dierks, T. and E. Rescorla, "The Transport Layer Security 1733 (TLS) Protocol Version 1.2", RFC 5246, August 2008. 1735 [RFC5378] Bradner, S. and J. Contreras, "Rights Contributors Provide 1736 to the IETF Trust", BCP 78, RFC 5378, November 2008. 1738 [RFC5742] Alvestrand, H. and R. Housley, "IESG Procedures for 1739 Handling of Independent and IRTF Stream Submissions", BCP 1740 92, RFC 5742, December 2009. 1742 [RFC5771] Cotton, M., Vegoda, L. and D. Meyer, "IANA Guidelines for 1743 IPv4 Multicast Address Assignments", BCP 51, RFC 5771, 1744 March 2010. 1746 [RFC5795] Sandlund, K., Pelletier, G. and L-E. Jonsson, "The RObust 1747 Header Compression (ROHC) Framework", RFC 5795, March 1748 2010. 1750 [RFC6195] Eastlake, D., "Domain Name System (DNS) IANA 1751 Considerations", BCP 42, RFC 6195, March 2011. 1753 [RFC6275] Perkins, C., Johnson, D. and J. Arkko, "Mobility Support 1754 in IPv6", RFC 6275, July 2011. 1756 [RFC6709] Carpenter, B., Aboba, B. and S. Cheshire, "Design 1757 Considerations for Protocol Extensions", RFC 6709, 1758 September 2012. 1760 [RFC7120] Cotton, M., "Early IANA Allocation of Standards Track Code 1761 Points", BCP 100, RFC 7120, January 2014. 1763 Authors' Addresses 1765 Michelle Cotton 1766 Internet Corporation for Assigned Names and Numbers 1767 12025 Waterfront Drive, Suite 300 1768 Los Angeles, CA 90094-2536 1769 US 1771 Phone: +1 310 823 9358 1772 Email: michelle.cotton@icann.org 1773 URI: http://www.icann.org/ 1775 Barry Leiba 1776 Huawei Technologies 1778 Phone: +1 646 827 0648 1779 Email: barryleiba@computer.org 1780 URI: http://internetmessagingtechnology.org/ 1781 Thomas Narten 1782 IBM Corporation 1783 3039 Cornwallis Ave., PO Box 12195 - BRQA/502 1784 Research Triangle Park, NC 27709-2195 1785 US 1787 Phone: +1 919 254 7798 1788 Email: narten@us.ibm.com