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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: December 5, 2014 IBM Corporation 8 June 3, 2014 10 Guidelines for Writing an IANA Considerations Section in RFCs 11 draft-leiba-cotton-iana-5226bis-05 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 December 5, 2014. 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 56 (http://trustee.ietf.org/license-info) in effect on the date of 57 publication of this document. Please review these documents 58 carefully, as they describe your rights and restrictions with respect 59 to this document. Code Components extracted from this document must 60 include Simplified BSD License text as described in Section 4.e of 61 the Trust Legal Provisions and are provided without warranty as 62 described in the Simplified BSD License. 64 Table of Contents 66 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 3 67 1.1. Keep IANA Considerations for IANA . . . . . . . . . . . . 4 68 1.2. For More Information . . . . . . . . . . . . . . . . . . 4 69 1.3. Terminology Used In This Document . . . . . . . . . . . . 5 70 2. Creating and Revising Registries . . . . . . . . . . . . . . 5 71 2.1. Hierarchical Registry Structure . . . . . . . . . . . . . 5 72 2.2. Documentation Requirements for Registries . . . . . . . . 7 73 2.3. Defining an Appropriate Registry Policy . . . . . . . . . 9 74 2.3.1. Using the Well-Known Registration Policies . . . . . 11 75 2.3.2. Using Multiple Policies in Combination . . . . . . . 13 76 2.3.3. Specifying Change Control for a Registry . . . . . . 13 77 2.4. Revising Existing Registries . . . . . . . . . . . . . . 14 78 3. Registering New Values in an Existing Registry . . . . . . . 14 79 3.1. Documentation Requirements for Registrations . . . . . . 14 80 3.2. Updating Existing Registrations . . . . . . . . . . . . . 16 81 3.3. Overriding Registration Procedures . . . . . . . . . . . 16 82 3.4. Early Allocations . . . . . . . . . . . . . . . . . . . . 17 83 4. Well-Known Registration Policies . . . . . . . . . . . . . . 17 84 4.1. Private Use . . . . . . . . . . . . . . . . . . . . . . . 18 85 4.2. Experimental Use . . . . . . . . . . . . . . . . . . . . 18 86 4.3. Hierarchical Allocation . . . . . . . . . . . . . . . . . 18 87 4.4. First Come First Served . . . . . . . . . . . . . . . . . 19 88 4.5. Expert Review . . . . . . . . . . . . . . . . . . . . . . 19 89 4.6. Specification Required . . . . . . . . . . . . . . . . . 20 90 4.7. RFC Required . . . . . . . . . . . . . . . . . . . . . . 20 91 4.8. IETF Review . . . . . . . . . . . . . . . . . . . . . . . 20 92 4.9. Standards Action . . . . . . . . . . . . . . . . . . . . 21 93 4.10. IESG Approval . . . . . . . . . . . . . . . . . . . . . . 21 94 5. Designated Experts . . . . . . . . . . . . . . . . . . . . . 22 95 5.1. The Motivation for Designated Experts . . . . . . . . . . 22 96 5.2. The Role of the Designated Expert . . . . . . . . . . . . 23 97 5.3. Designated Expert Reviews . . . . . . . . . . . . . . . . 24 98 5.4. Expert Reviews and the Document Lifecycle . . . . . . . . 26 99 6. Well-Known Registration Status Terminology . . . . . . . . . 26 100 7. Documentation References in IANA Registries . . . . . . . . . 27 101 8. What to Do in "bis" Documents . . . . . . . . . . . . . . . . 27 102 9. Miscellaneous Issues . . . . . . . . . . . . . . . . . . . . 29 103 9.1. When There Are No IANA Actions . . . . . . . . . . . . . 29 104 9.2. Namespaces Lacking Documented Guidance . . . . . . . . . 29 105 9.3. After-the-Fact Registrations . . . . . . . . . . . . . . 30 106 9.4. Reclaiming Assigned Values . . . . . . . . . . . . . . . 30 107 9.5. Contact Person vs Assignee or Owner . . . . . . . . . . . 31 108 9.6. Closing or Obsoleting a Registry . . . . . . . . . . . . 31 109 10. Appeals . . . . . . . . . . . . . . . . . . . . . . . . . . . 31 110 11. Mailing Lists . . . . . . . . . . . . . . . . . . . . . . . . 32 111 12. Security Considerations . . . . . . . . . . . . . . . . . . . 32 112 13. Changes Relative to Earlier Editions of BCP 26 . . . . . . . 32 113 13.1. 2013: Changes in This Document Relative to RFC 5226 . . 32 114 13.2. 2008: Changes in RFC 5226 Relative to RFC 2434 . . . . . 33 115 14. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . 34 116 14.1. Acknowledgments for This Document (2013) . . . . . . . . 34 117 14.2. Acknowledgments from the second edition (2008) . . . . . 35 118 14.3. Acknowledgments from the first edition (1998) . . . . . 35 119 15. References . . . . . . . . . . . . . . . . . . . . . . . . . 35 120 15.1. Normative References . . . . . . . . . . . . . . . . . . 35 121 15.2. Informative References . . . . . . . . . . . . . . . . . 35 122 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 38 124 1. Introduction 126 Many protocols make use of points of extensibility that use constants 127 to identify various protocol parameters. To ensure that the values 128 used in these fields do not have conflicting uses, and to promote 129 interoperability, their allocation is often coordinated by a central 130 authority. For IETF protocols, that role is filled by the Internet 131 Assigned Numbers Authority (IANA) [RFC2860]. IANA services are 132 currently provided by the International Corporation for Assigned 133 Names and Numbers (ICANN). 135 The Protocol field in the IP header [RFC0791] and MIME media types 136 [RFC4288] are two examples of such coordinations. 138 In this document, we call the range of possible values for such a 139 field a "namespace". The binding or association of a specific value 140 with a particular purpose within a namespace is called an assignment 141 (or, variously: an assigned number, assigned value, code point, 142 protocol constant, or protocol parameter). The act of assignment is 143 called a registration, and it takes place in the context of a 144 registry. The terms "assignment" and "registration" are used 145 interchangably throughout this document. 147 To make assignments in a given namespace prudently, IANA needs 148 guidance describing the conditions under which new values should be 149 assigned, as well as when and how modifications to existing values 150 can be made. This document defines a framework for the documentation 151 of these guidelines by specification authors, in order to assure that 152 the guidance given to IANA is clear and addresses the various issues 153 that are likely in the operation of a registry. 155 Typically, this information is recorded in a dedicated section of the 156 specification with the title "IANA Considerations". 158 1.1. Keep IANA Considerations for IANA 160 The purpose of having a dedicated IANA Considerations section is to 161 provide a single place to collect clear and concise information and 162 instructions for IANA. Technical documentation should reside in 163 other parts of the document, and should be included by reference 164 only. Using the IANA Considerations section as primary technical 165 documentation both hides it from the target audience of the document 166 and interferes with IANA's review of the actions they need to take. 168 If, for example, the registration of an item in a registry includes a 169 short description of the item being registered, that should be placed 170 in the IANA Considerations directly. But if it's necessary to 171 include a longer technical explanation of the purpose and use of the 172 item, the IANA Considerations should refer to a technical section of 173 the document where that information resides. 175 An ideal IANA Considerations section clearly enumerates and specifies 176 each requested IANA action; includes all information IANA needs, such 177 as the full names of all applicable registries; and includes clear 178 references to elsewhere in the document for other information. 180 1.2. For More Information 182 IANA maintains a web page that includes current important information 183 from IANA. Document authors should check that page for additional 184 information, beyond what is provided here. 186 . 188 [[CREF1: ***** The URI above is not yet ready. Make sure IANA sets 189 it up. *****]] 191 1.3. Terminology Used In This Document 193 The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", 194 "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this 195 document are to be interpreted as described in RFC 2119 [RFC2119]. 196 For this document, "the specification" as used by RFC 2119 refers to 197 the processing of protocol documents within the IETF standards 198 process. 200 2. Creating and Revising Registries 202 Defining a registry involves describing the namespace(s) to be 203 created, listing an initial set of assignments (if appropriate), and 204 documenting guidelines on how future assignments are to be made. 206 Before defining a registry, however, consider delegating the 207 namespace in some manner. This route should be pursued when 208 appropriate, as it lessens the burden on IANA for dealing with 209 assignments. 211 In particular, not all namespaces require a registry; in some cases, 212 assignments can be made independently and with no further (central) 213 coordination. In the Domain Name System, for example, IANA only 214 deals with assignments at the higher levels, while subdomains are 215 administered by the organization to which the space has been 216 delegated. When a namespace is delegated in this manner, the scope 217 of IANA is limited to the parts of the namespace where IANA has 218 authority. 220 2.1. Hierarchical Registry Structure 222 It's important to start with a word on the IANA registry structure. 223 All registries are anchored from the IANA "Protocol Registries" page: 225 . 227 That page lists registries in groups, like this: 229 --------------------------------------------------------------- 230 Author Domain Signing Practices (ADSP) Parameters 232 ADSP Outbound Signing Practices RFC 5617 233 IETF Review 235 ADSP Specification Tags RFC 5617 236 IETF Review 238 Automatic Responses to Electronic Mail Parameters 240 Auto-Submitted Header Field RFC 5436 241 Keywords Specification Required 243 Auto-Submitted header field RFC 3834 244 optional parameters IETF Consensus 246 Autonomous System (AS) Numbers 248 16-bit Autonomous System Numbers RFC 1930, RFC 5398, RFC 6996 249 RIR request to the IANA 250 or IETF Review 252 32-bit Autonomous System Numbers RFC 1930, RFC 5398, RFC 6793, 253 RFC 6996 254 RIR request to the IANA 255 or IETF Review 256 --------------------------------------------------------------- 258 The grouping allows related registries to be placed together, making 259 it easier for users of the registries to find the necessary 260 information. In the example section above, there are two registries 261 related to the ADSP protocol, and they are both placed in the "ADSP 262 Parameters" group. 264 Within the "ADSP Parameters" group are two registries: "ADSP Outbound 265 Signing Practices" and "ADSP Specification Tags". Clicking on the 266 title of one of these registries on the IANA Protocol Registries page 267 will take the reader to the details page for that registry. Often, 268 multiple registries are shown on the same details page. 270 Unfortunately, we have been inconsistent in how we refer to these 271 entities. The group names, as they are referred to here, have been 272 variously called "groups", "top-level registries", or just 273 "registries". The registries under them have been called 274 "registries" or "sub-registries". And when new registries are 275 created, the documents that define them often don't specify the 276 grouping at all, but only name the new registry. This results in 277 questions from IANA and delays in processing, or, worse, in related 278 registries that should have been grouped together, but that are 279 instead scattered about and hard to find and correlate. 281 Regardless of the terminology used, document authors should pay 282 attention to the registry groupings, should request that related 283 registries be grouped together, and, when creating a new registry, 284 should check whether that registry might best be included in an 285 existing group. That grouping information should be clearly 286 communicated to IANA in the registry creation request. 288 2.2. Documentation Requirements for Registries 290 Documents that create a new namespace (or modify the definition of an 291 existing space) and that expect IANA to play a role in maintaining 292 that space (serving as a repository for registered values) MUST 293 provide clear instructions on details of the namespace, either in the 294 IANA Considerations section, or referenced from it. 296 In particular, such instructions MUST include: 298 The name of the registry (or sub-registry) 299 This name will appear on the IANA web page and will be referred to 300 in future documents that need to allocate a value from the new 301 space. The full name (and abbreviation, if appropriate) should be 302 provided. It is highly desirable that the chosen name not be 303 easily confused with the name of another registry. 305 When creating a sub-registry, the registry that it is a part of 306 must be identified using its full name, exactly as it appears in 307 the IANA registry list. 309 Providing a URL to precisely identify the registry helps IANA 310 understand the request. Such URLs can be removed from the RFC 311 prior to final publication. If they are to be left in, it is 312 important that they be permanent links -- IANA intends to include 313 the permalink for each registry in the registry header. 315 For example, a document could contain something like this: 317 This registration should be made in the Foobar Operational 318 Parameters registry, located at . 321 It might be tempting to use the URL that appears in your web 322 browser's address bar, which might look something like this for 323 the example above: 325 http://www.iana.org/assignments/foobar-registry/foobar- 326 registry.xml 328 ...but that is not the permanent link to the registry. 330 Required information for registrations 332 This information may include the need to document relevant 333 Security Considerations, if any. 335 Applicable review process 337 The review process that will apply to all future requests for 338 registration. See Section 2.3. 340 Size, format and syntax of registry entries 342 What fields to record in the registry., and any technical 343 requirements upon registry entries (e.g., valid ranges for 344 integers, length limitations on strings, etc.) as well as the 345 exact format in which registry values should be displayed. For 346 numeric assignments, one should specify whether values are to be 347 recorded in decimal, hexadecimal, or some other format. For 348 strings, the encoding format should be specified (ASCII, UTF8, 349 etc.). 351 Initial assignments and reservations 353 Any initial assignments or registrations to be included. In 354 addition, any ranges that are to be reserved for "Private Use", 355 "Reserved", "Unassigned", etc. should be indicated. 357 For example, a document might specify a new registry by including: 359 --------------------------------------------------------------- 361 X. IANA Considerations 363 This document defines a new DHCP option, entitled "FooBar" (see 364 Section y), assigned a value of TBD1 from the DHCP Option space 365 [to be removed upon publication: 366 http://www.iana.org/assignments/bootp-dhcp-parameters] 367 [RFC2132] [RFC2939]: 368 Data 369 Tag Name Length Meaning 370 ---- ---- ------ ------- 371 TBD1 FooBar N FooBar server 373 The FooBar option also defines an 8-bit FooType field, for which 374 IANA is to create and maintain a new sub-registry entitled 375 "FooType values" under the FooBar option. Initial values for the 376 DHCP FooBar FooType registry are given below; future assignments 377 are to be made through Expert Review [BCP26]. 378 Assignments consist of a DHCP FooBar FooType name and its 379 associated value. 381 Value DHCP FooBar FooType Name Definition 382 ---- ------------------------ ---------- 383 0 Reserved 384 1 Frobnitz See Section y.1 385 2 NitzFrob See Section y.2 386 3-254 Unassigned 387 255 Reserved 388 --------------------------------------------------------------- 390 For examples of documents that establish registries, consult 391 [RFC6195], [RFC3575], [RFC3968], and [RFC4520]. 393 2.3. Defining an Appropriate Registry Policy 395 There are several issues to consider when defining the policy for the 396 new assignments in a registry. 398 If the registry's namespace is limited, assignments will need to be 399 made carefully to prevent exhaustion. 401 Even when the space is essentially unlimited, however, it is usually 402 desirable to have at least a minimal review prior to assignment in 403 order to: 405 o prevent the hoarding of or unnecessary wasting of values. For 406 example, if the space consists of text strings, it may be 407 desirable to prevent entities from obtaining large sets of strings 408 that correspond to desirable names (existing company names, for 409 example). 411 o provide a sanity check that the request actually makes sense and 412 is necessary. Experience has shown that some level of minimal 413 review from a subject matter expert is useful to prevent 414 assignments in cases where the request is malformed or not 415 actually needed (for example, an existing assignment for an 416 essentially equivalent service already exists). 418 Perhaps most importantly, unreviewed extensions can impact 419 interoperability and security. See [RFC6709]. 421 When the namespace is essentially unlimited and there are no 422 potential interoperability or security issues, assigned numbers can 423 usually be given out to anyone without any subjective review. In 424 such cases, IANA can make assignments directly, provided that IANA is 425 given detailed instructions on what types of requests it should 426 grant, and it is able to do so without exercising subjective 427 judgement. 429 When this is not the case, some level of review is required. 430 However, it's important to balance adequate review and ease of 431 registration. In many cases, those making registrations will not be 432 IETF participants; requests often come from other standards 433 organizations, from organizations not directly involved in standards, 434 from ad-hoc community work (from an open-source project, for 435 example), and so on. Registration must not be unnecessarily 436 difficult, unnecessarily costly (in terms of time and other 437 resources), nor unnecessarily subject to denial. 439 While it is sometimes necessary to restrict what gets registered 440 (e.g., for limited resources such as bits in a byte, or for items for 441 which unsupported values can be damaging to protocol operation), in 442 many cases having what's in use represented in the registry is more 443 important. Overly strict review criteria and excessive cost (in time 444 and effort) discourage people from even attempting to make a 445 registration. If a registry fails to reflect the protocol elements 446 actually in use, it can adversely affect deployment of protocols on 447 the Internet, and the registry itself is devalued. 449 In particular, when a registry policy that requires involvement of 450 Working Groups, directorates, or other bodies to be actively involved 451 and to support the effort, requests frequently run into concerns that 452 "it's not worth doing a Standards-Track RFC for something this 453 trivial," when, in fact, that requirement was created by the Working 454 Group in the first place, by placing the bar that high. 456 Indeed, publishing any RFC is costly, and a Standards Track RFC is 457 especially so, requiring a great deal of community time for review 458 and discussion, IETF-wide last call, involvement of the entire IESG 459 as well as concentrated time and review from the sponsoring AD, 460 review and action by IANA, and RFC-Editor processing. 462 Therefore, Working Groups and other document developers should use 463 care in selecting appropriate registration policies when their 464 documents create registries. They should select the least strict 465 policy that suits a registry's needs, and look for specific 466 justification for policies that require significant community 467 involvement (Specification Required, in terms of the well-known 468 policies). 470 2.3.1. Using the Well-Known Registration Policies 472 This document defines a number of registration policies in Section 4. 473 Because they benefit from both community experience and wide 474 understanding, their use is encouraged when appropriate. 476 It is also acceptable to cite one of the well-known policies and 477 include additional guidelines for what kind of considerations should 478 be taken into account by the review process. 480 For example, RADIUS [RFC3575] specifies the use of a Designated 481 Expert, but includes specific additional criteria the Designated 482 Expert should follow. 484 The well-known policies from "First Come First Served" to "Standards 485 Action" specify a range of policies in increasing order of 486 strictness: 488 4. First Come First Served 489 No review, minimal documentation. 491 5. Expert Review 492 Expert review, sufficient documentation for review. 494 6. Specification Required 495 Expert review, significant, stable public documentation. 497 7. RFC Required 498 Any RFC publication, IETF or a non-IETF Stream. 500 8. IETF Review 501 RFC publication, IETF Stream only, but need not be Standards 502 Track. 504 9. Standards Action 505 RFC publication, IETF Stream, Standards Track only. 507 Examples of situations that might merit RFC Required, IETF Review, or 508 Standards Action include the following: 510 o When a resource is limited, such as bits in a byte (or in two 511 bytes, or four), or numbers in a limited range. In these cases, 512 allowing registrations that haven't been carefully reviewed and 513 agreed by community consensus could too quickly deplete the 514 allowable values. 516 o When thorough community review is necessary to avoid extending or 517 modifying the protocol in ways that could be damaging. One 518 example is in defining new command codes, as opposed to options 519 that use existing command codes: the former might require a strict 520 policy, where a more relaxed policy could be adequate for the 521 latter. Another example is in defining protocol elements that 522 change the semantics of existing operations. 524 The description in Section 4.10 of "IESG Approval" suggests that the 525 IESG "can (and should) reject a request if another path for 526 registration is available that is more appropriate and there is no 527 compelling reason not to use that path." The IESG should give 528 similar consideration to any registration policy more stringent than 529 Specification Required, asking for justification and ensuring that 530 more relaxed policies have been considered, and the strict policy is 531 the right one. 533 Accordingly, document developers need to anticipate this and document 534 their considerations for selecting the specified policy (ideally, in 535 the document itself; failing that, in the shepherd writeup). 536 Likewise, the document shepherd should ensure that the selected 537 policies have been justified before sending the document to the IESG. 539 When specifications are revised, registration policies should be 540 reviewed in light of experience since the policies were set. 542 Note that the well-known policies are not exclusive; there are 543 situations where a different policy might be more appropriate. 545 2.3.2. Using Multiple Policies in Combination 547 In some situations, it is necessary to define multiple registration 548 policies. For example, registrations through the normal IETF process 549 might use one policy, while registrations from outside the process 550 would have a different policy applied. 552 Thus, a particular registry might want to use a policy such as "RFC 553 Required" or "IETF Review" sometimes, with a designated expert 554 checking a "Specification Required" policy at other times. 556 The alternative to using a combination requires either that all 557 requests come through RFCs or that requests in RFCs go through review 558 by the designated expert, even though they already have IETF review 559 and consensus. 561 This can be documented in the IANA Considerations section when the 562 registry is created: 564 IANA is asked to create the registry "Fruit Access Flags" as a 565 sub-registry of "Fruit Parameters". New registrations will be 566 permitted through either the IETF Review policy or the 567 Specification Required policy [BCP26]. 569 Such combinations will commonly use one of {Standards Action, IETF 570 Review, RFC Required} in combination with one of {Specification 571 Required, Expert Review}. 573 2.3.3. Specifying Change Control for a Registry 575 Registry definitions and registrations within registries often need 576 to be changed after they are created. The process of making such 577 changes is complicated when it is unclear who is authorized to make 578 the changes. For registries created by RFCs in the IETF stream, 579 change control for the registry lies by default with the IETF, via 580 the IESG. The same is true for value registrations made in IETF- 581 stream RFCs. 583 But registries can be created and registrations can be made outside 584 the IETF stream, it can sometimes be desired to have change control 585 outside the IETF and IESG, and clear specification of change control 586 policies is always helpful. 588 It is advised, therefore, that all registries that are created 589 clearly specify a change control policy and a change controller. It 590 is also advised that registries that allow registrations from outside 591 the IETF stream include, for each value, the designation of a change 592 controller for that value. If the definition or reference for a 593 registered value ever needs to change, or if a registered value needs 594 to be deprecated, it is critical that IANA know who is authorized to 595 make the change. 597 2.4. Revising Existing Registries 599 Updating the registration process for an already existing (previously 600 created) namespace (whether created explicitly or implicitly) follows 601 a process similar to that used when creating a new namespace. That 602 is, a document is produced that makes reference to the existing 603 namespace and then provides detailed guidelines for handling 604 assignments in each individual namespace. Such documents are 605 normally processed as Best Current Practices (BCPs) [RFC2026]. 607 Example documents that updated the guidelines for assignments in pre- 608 existing registries include: [RFC6195], [RFC3228], and [RFC3575]. 610 3. Registering New Values in an Existing Registry 612 3.1. Documentation Requirements for Registrations 614 Often, documents request an assignment from an already existing 615 namespace (one created by a previously published document). 617 Such documents should clearly identify the namespace in which each 618 value is to be registered. If the registration goes into a sub- 619 registry, the author should clearly describe where the assignment or 620 registration should go. Use the exact namespace name as listed on 621 the IANA web page, and cite the RFC where the namespace is defined. 623 There is no need to mention what the assignment policy for new 624 assignments is, as that should be clear from the references. 626 When referring to an existing registry, providing a URL to precisely 627 identify the registry is helpful. See Section 2.2 for details on 628 specifying the correct URL. 630 For example, a document could contain something like this: 632 This registration should be made in the Foobar Operational 633 Parameters registry, located at . 636 Each value requested should be given a unique reference. When the 637 value is numeric, use the notation: TBD1, TBD2, etc. Throughout the 638 document where an actual IANA-assigned value should be filled in, use 639 the "TBDx" notation. This helps ensure that the final RFC has the 640 correct assigned values inserted in all of the relevant places where 641 the value is expected to appear in the final document. For values 642 that are text strings, a specific name can be suggested. IANA will 643 normally assign the name, unless it conflicts with a name already in 644 use. 646 Normally, the values to be used are chosen by IANA and documents 647 should specify values of "TBD". However, in some cases, a value may 648 have been used for testing or in early implementations. In such 649 cases, it is acceptable to include text suggesting what specific 650 value should be used (together with the reason for the choice). For 651 example, one might include the text "the value XXX is suggested as it 652 is used in implementations". However, it should be noted that 653 suggested values are just that; IANA will attempt to assign them, but 654 may find that impossible, if the proposed number has already been 655 assigned for some other use. 657 For some registries, IANA has a long-standing policy prohibiting 658 assignment of names or codes on a vanity or organization-name basis. 659 For example, codes are always assigned sequentially unless there is a 660 strong reason for making an exception. Nothing in this document is 661 intended to change those policies or prevent their future 662 application. 664 The IANA Considerations section should summarize all of the IANA 665 actions, with pointers to the relevant sections elsewhere in the 666 document as appropriate. When multiple values are requested, it is 667 generally helpful to include a summary table. It is also helpful for 668 this table to be in the same format as it appears or will appear on 669 the IANA web site. For example: 671 Value Description Reference 672 -------- ------------------- --------- 673 TBD1 Foobar [[this RFC]] 675 Note: In cases where authors feel that including the full table is 676 too verbose or repetitive, authors should still include the table in 677 the draft, but may include a note asking that the table be removed 678 prior to publication of the final RFC. 680 As an example, the following text could be used to request assignment 681 of a DHCPv6 option number: 683 IANA has assigned an option code value of TBD1 to the DNS 684 Recursive Name Server option and an option code value of TBD2 to 685 the Domain Search List option from the DHCP option code space 686 defined in Section 24.3 of RFC 3315. 688 3.2. Updating Existing Registrations 690 Even after a number has been assigned, some types of registrations 691 contain additional information that may need to be updated over time. 693 For example, MIME media types, character sets, and language tags 694 typically include more information than just the registered value 695 itself, and may need things such as point-of-contact information, 696 security issues, pointers to updates, or literature references 697 updated. 699 In such cases, the document defining the namespace must clearly state 700 who is responsible for maintaining and updating a registration. 701 Depending on the registry, it may be appropriate to specify one or 702 more of: 704 o Letting registrants and/or nominated change controllers update 705 their own registrations, subject to the same constraints and 706 review as with new registrations. 708 o Allowing attachment of comments to the registration. This can be 709 useful in cases where others have significant objections to a 710 registration, but the author does not agree to change the 711 registration. 713 o Designating the IESG, a designated expert, or another entity as 714 having the right to change the registrant associated with a 715 registration and any requirements or conditions on doing so. This 716 is mainly to get around the problem when a registrant cannot be 717 reached in order to make necessary updates. 719 3.3. Overriding Registration Procedures 721 Experience has shown that the documented IANA considerations for 722 individual protocols do not always adequately cover the reality of 723 registry operation, or are not sufficiently clear. In addition, 724 documented IANA considerations are sometimes found to be too 725 stringent to allow even working group documents (for which there is 726 strong consensus) to perform a registration in advance of actual RFC 727 publication. 729 In order to allow assignments in such cases, the IESG is granted 730 authority to override registration procedures and approve assignments 731 on a case-by-case basis. 733 The intention here is not to overrule properly documented procedures, 734 or to obviate the need for protocols to properly document their IANA 735 considerations. Rather, it is to permit assignments in specific 736 cases where it is obvious that the assignment should just be made, 737 but updating the IANA process beforehand is too onerous. 739 When the IESG is required to take action as described in this 740 section, it is a strong indicator that the applicable registration 741 procedures should be updated, possibly in parallel with the work that 742 instigated it. 744 3.4. Early Allocations 746 IANA normally takes its actions when a document is approved for 747 publication. There are times, though, when early allocation of a 748 value is important for the development of a technology: for example, 749 when early implementations are created while the document is still 750 under development. 752 IANA has a mechanism for handling such early allocations in some 753 cases. See [I-D.cotton-rfc4020bis] for details. 755 4. Well-Known Registration Policies 757 The following are some defined policies, most of which are in use 758 today. These cover a range of typical policies that have been used 759 to describe the procedure for assigning new values in a namespace. 760 It is not strictly required that documents use these terms; the 761 actual requirement is that the instructions to IANA be clear and 762 unambiguous. However, use of these terms is strongly RECOMMENDED, 763 because their meanings are widely understood. The terms are fully 764 explained in the following subsections. 766 1. Private Use 767 2. Experimental Use 768 3. Hierarchical Allocation 769 4. First Come First Served 770 5. Expert Review 771 6. Specification Required 772 7. RFC Required 773 8. IETF Review 774 9. Standards Action 775 10. IESG Approval 777 It should be noted that it often makes sense to partition a namespace 778 into multiple categories, with assignments within each category 779 handled differently. Many protocols now partition namespaces into 780 two or more parts, with one range reserved for Private or 781 Experimental Use while other ranges are reserved for globally unique 782 assignments assigned following some review process. Dividing a 783 namespace into ranges makes it possible to have different policies in 784 place for different ranges and different use cases. 786 Similarly, it will often be useful to specify multiple policies in 787 parallel, with each policy being used under different circumstances. 788 For more discussion of that topic, see Section 2.3.2. 790 Examples: 792 LDAP [RFC4520] 793 TLS ClientCertificateType Identifiers [RFC5246] (as detailed in 794 the subsections below) 795 Pseudowire Edge to Edge Emulation (PWE3) [RFC4446] 797 4.1. Private Use 799 For private or local use only, with the type and purpose defined by 800 the local site. No attempt is made to prevent multiple sites from 801 using the same value in different (and incompatible) ways. There is 802 no need for IANA to review such assignments (since IANA does not 803 record them) and assignments are not generally useful for broad 804 interoperability. It is the responsibility of the sites making use 805 of the Private Use range to ensure that no conflicts occur (within 806 the intended scope of use). 808 Examples: 810 Site-specific options in DHCP [RFC2939] 811 Fibre Channel Port Type Registry [RFC4044] 812 TLS ClientCertificateType Identifiers 224-255 [RFC5246] 814 4.2. Experimental Use 816 Experimental Use is similar to Private Use only, but with the purpose 817 being to facilitate experimentation. See [RFC3692] for details. 819 Example: 821 Experimental Values in IPv4, IPv6, ICMPv4, ICMPv6, UDP, and TCP 822 Headers [RFC4727] 824 4.3. Hierarchical Allocation 826 With Hierarchical Allocation, delegated administrators are given 827 control over part of the namespace, and can assign values in that 828 part of the namespace. IANA makes allocations in the higher levels 829 of the namespace according to one of the other policies. 831 Examples: 833 DNS names 834 Object Identifiers 835 IP addresses 837 4.4. First Come First Served 839 For the First Come First Served policy, assignments are made to 840 anyone on a first come, first served basis. There is no substantive 841 review of the request, other than to ensure that it is well-formed 842 and doesn't duplicate an existing assignment. However, requests must 843 include a minimal amount of clerical information, such as a point of 844 contact (including an email address, and sometimes a postal address) 845 and a brief description of how the value will be used. Additional 846 information specific to the type of value requested may also need to 847 be provided, as defined by the namespace. For numbers, the exact 848 value is generally assigned by IANA; with names, specific text 849 strings can usually be requested. 851 Examples: 853 SASL mechanism names [RFC4422] 854 LDAP Protocol Mechanisms and LDAP Syntax [RFC4520] 856 4.5. Expert Review 858 (Also called "Designated Expert" in earlier editions of this 859 document.) For the Expert Review policy, review and approval by a 860 designated expert (see Section 5) is required. The required 861 documentation and review criteria for use by the designated expert 862 should be provided when defining the registry. For example, see 863 Sections 6 and 7.2 in [RFC3748]. 865 It is particularly important, when using a designated expert, to give 866 clear guidance to the expert, laying out criteria for performing an 867 evaluation and reasons for rejecting a request. When specifying a 868 policy that involves a designated expert, the IANA Considerations 869 SHOULD contain such guidance. It is also a good idea to include, 870 when possible, a sense of whether many registrations are expected 871 over time, or if the registry is expected to be updated infrequently 872 or in exceptional circumstances only. 874 Examples: 876 EAP Method Types [RFC3748] 877 HTTP Digest AKA algorithm versions [RFC4169] 878 URI schemes [RFC4395] 879 GEOPRIV Location Types [RFC4589] 881 4.6. Specification Required 883 For the Specification Required policy, review and approval by a 884 designated expert (see Section 5) is required, and the values and 885 their meanings must be documented in a permanent and readily 886 available public specification, in sufficient detail so that 887 interoperability between independent implementations is possible. 888 The designated expert will review the public specification and 889 evaluate whether it is sufficiently clear to allow interoperable 890 implementations. The intention behind "permanent and readily 891 available" is that a document can reasonably be expected to be 892 findable and retrievable long after IANA assignment of the requested 893 value. Publication of an RFC is an ideal means of achieving this 894 requirement, but Specification Required is intended to also cover the 895 case of a document published outside of the RFC path. For RFC 896 publication, the normal RFC review process is expected to provide the 897 necessary review for interoperability, though the designated expert 898 may be a particularly well-qualified person to perform such a review. 900 When specifying this policy, just use the term "Specification 901 Required". Some specifications have chosen to refer to it as "Expert 902 Review with Specification Required", and that only causes confusion. 904 Examples: 906 Diffserv-aware TE Bandwidth Constraints Model Identifiers 907 [RFC4124] 908 TLS ClientCertificateType Identifiers 64-223 [RFC5246] 909 ROHC Profile Identifiers [RFC5795] 911 4.7. RFC Required 913 With the RFC Required policy, the registration request, along with 914 associated documentation, must be published in an RFC. The RFC need 915 not be in the IETF stream, but may be in any RFC stream (currently an 916 RFC may be in the IETF, IRTF, or IAB stream, or an RFC Editor 917 Independent Submission [RFC5742]). Unless otherwise specified, any 918 type of RFC is sufficient (currently Standards Track, BCP, 919 Informational, Experimental, or Historic). 921 4.8. IETF Review 923 (Formerly called "IETF Consensus" in the first edition of this 924 document.) With the IETF Review policy, new values are assigned only 925 through RFCs in the IETF Stream -- those that have been shepherded 926 through the IESG as AD-Sponsored or IETF working group Documents 927 [RFC2026] [RFC5378]. 929 The intent is that the document and proposed assignment will be 930 reviewed by the IETF community (including appropriate IETF working 931 groups, directorates, and other experts) and by the IESG, to ensure 932 that the proposed assignment will not negatively affect 933 interoperability or otherwise extend IETF protocols in an 934 inappropriate or damaging manner. To ensure adequate community 935 review, such documents will always undergo an IETF Last Call. 937 Examples: 939 IPSECKEY Algorithm Types [RFC4025] 940 Accounting-Auth-Method AVP values in DIAMETER [RFC4005] 941 TLS Extension Types [RFC5246] 943 4.9. Standards Action 945 For the Standards Action policy, values are assigned only through 946 Standards Track RFCs approved by the IESG. 948 Examples: 950 BGP message types [RFC4271] 951 Mobile Node Identifier option types [RFC4283] 952 TLS ClientCertificateType Identifiers 0-63 [RFC5246] 953 DCCP Packet Types [RFC4340] 955 4.10. IESG Approval 957 New assignments may be approved by the IESG. Although there is no 958 requirement that the request be documented in an RFC, the IESG has 959 discretion to request documents or other supporting materials on a 960 case-by-case basis. 962 IESG Approval is not intended to be used often or as a "common case"; 963 indeed, it has seldom been used in practice during the period RFC 964 2434 was in effect. Rather, it is intended to be available in 965 conjunction with other policies as a fall-back mechanism in the case 966 where one of the other allowable approval mechanisms cannot be 967 employed in a timely fashion or for some other compelling reason. 968 IESG Approval is not intended to circumvent the public review 969 processes implied by other policies that could have been employed for 970 a particular assignment. IESG Approval would be appropriate, 971 however, in cases where expediency is desired and there is strong 972 consensus (such as from a working group) for making the assignment. 974 The following guidelines are suggested for any evaluation under IESG 975 Approval: 977 o The IESG can (and should) reject a request if another path for 978 registration is available that is more appropriate and there is no 979 compelling reason not to use that path. 981 o Before approving a request, the community should be consulted, via 982 a "call for comments" that provides as much information as is 983 reasonably possible about the request. 985 Examples: 987 IPv4 Multicast address assignments [RFC5771] 988 IPv4 IGMP Type and Code values [RFC3228] 989 Mobile IPv6 Mobility Header Type and Option values [RFC6275] 991 5. Designated Experts 993 5.1. The Motivation for Designated Experts 995 IANA does not define registry policy itself; rather, it carries out 996 policies that have been defined by others and published in RFCs. As 997 part of that process, review of proposed registrations is often 998 appropriate. 1000 A common way to ensure such review is for a proposed registration to 1001 be published as an RFC, as this ensures that the specification is 1002 publicly and permanently available. It is particularly important if 1003 any potential interoperability issues might arise. For example, some 1004 assignments are not just assignments, but also involve an element of 1005 protocol specification. A new option may define fields that need to 1006 be parsed and acted on, which (if specified poorly) may not fit 1007 cleanly with the architecture of other options or the base protocols 1008 on which they are built. 1010 In some cases, however, the burden of publishing an RFC in order to 1011 register a protocol element is excessive. 1013 However, it is generally still useful (and sometimes necessary) to 1014 discuss proposed registrations within the community, on a mailing 1015 list. Such a mailing list provides opportunity for public review 1016 prior to assignment, and allows for a consultative process when 1017 registrants want help in understanding what a proper registration 1018 should contain. 1020 While discussion on a mailing list can provide valuable technical 1021 feedback, opinions may vary and discussions may continue for some 1022 time without clear resolution. In addition, IANA cannot participate 1023 in all of these mailing lists and cannot determine if or when such 1024 discussions reach consensus. Therefore, IANA relies on a "designated 1025 expert" for advice regarding the specific question of whether an 1026 assignment should be made. The designated expert is an individual 1027 who is responsible for carrying out an appropriate evaluation and 1028 returning a recommendation to IANA. 1030 It should be noted that a key motivation for having designated 1031 experts is for the IETF to provide IANA with a subject matter expert 1032 to whom the evaluation process can be delegated. IANA forwards 1033 requests for an assignment to the expert for evaluation, and the 1034 expert (after performing the evaluation) informs IANA as to whether 1035 or not to make the assignment or registration. 1037 It will often be useful to use a designated expert only some of the 1038 time, as a supplement to other processes. For more discussion of 1039 that topic, see Section 2.3.2. 1041 5.2. The Role of the Designated Expert 1043 The designated expert is responsible for coordinating the appropriate 1044 review of an assignment request. The review may be wide or narrow, 1045 depending on the situation and the judgment of the designated expert. 1046 This may involve consultation with a set of technology experts, 1047 discussion on a public mailing list, consultation with a working 1048 group (or its mailing list if the working group has disbanded), etc. 1049 Ideally, the designated expert follows specific review criteria as 1050 documented with the protocol that creates or uses the namespace. See 1051 the IANA Considerations sections of [RFC3748] and [RFC3575] for 1052 specific examples. 1054 Designated experts are expected to be able to defend their decisions 1055 to the IETF community, and the evaluation process is not intended to 1056 be secretive or bestow unquestioned power on the expert. Experts are 1057 expected to apply applicable documented review or vetting procedures, 1058 or in the absence of documented criteria, follow generally accepted 1059 norms such as those in Section 5.3. 1061 Designated experts are appointed by the IESG, normally upon 1062 recommendation by the relevant Area Director, either at the time a 1063 document creating or updating a namespace is approved by the IESG or 1064 subsequently, when the first registration request is received. 1065 Because experts originally appointed may later become unavailable, 1066 the IESG will appoint replacements as necessary. 1068 For some registries, it has proven useful to have multiple designated 1069 experts. Sometimes those experts work together in evaluating a 1070 request, while in other cases additional experts serve as backups. 1071 In cases of disagreement among those experts, it is the 1072 responsibility of those experts to make a single clear recommendation 1073 to IANA. It is not appropriate for IANA to resolve disputes among 1074 experts. In extreme situations, such as deadlock, the IESG may need 1075 to step in to resolve the problem. 1077 In registries where a pool of experts evaluates requests, the pool 1078 should have a single chair responsible for defining how requests are 1079 to be assigned to and reviewed by experts. In some cases, the expert 1080 pool may consist of a primary and backups, with the backups involved 1081 only when the primary expert is unavailable. In other cases, IANA 1082 might assign requests to individual members in sequential or 1083 approximate random order. In the event that IANA finds itself having 1084 received conflicting advice from its experts, it is the 1085 responsibility of the pool's chair to resolve the issue and provide 1086 IANA with clear instructions. 1088 A designated expert that is conflicted for a particular review (is, 1089 for example, an authors or significant proponent of a specification 1090 related to the registration under review), that expert should recuse 1091 himself. In the event that all the designated experts are 1092 conflicted, they should ask the IESG to designate a temporary expert 1093 for the conflicted review. 1095 As the designated experts are appointed by the IESG, they may be 1096 removed by the IESG. 1098 5.3. Designated Expert Reviews 1100 In the years since RFC 2434 was published and has been put to use, 1101 experience has led to the following observations: 1103 o A designated expert must respond in a timely fashion, normally 1104 within a week for simple requests to a few weeks for more complex 1105 ones. Unreasonable delays can cause significant problems for 1106 those needing assignments, such as when products need code points 1107 to ship. This is not to say that all reviews can be completed 1108 under a firm deadline, but they must be started, and the requester 1109 and IANA should have some transparency into the process if an 1110 answer cannot be given quickly. 1112 o If a designated expert does not respond to IANA's requests within 1113 a reasonable period of time, either with a response or with a 1114 reasonable explanation for the delay (some requests may be 1115 particularly complex), and if this is a recurring event, IANA must 1116 raise the issue with the IESG. Because of the problems caused by 1117 delayed evaluations and assignments, the IESG should take 1118 appropriate actions to ensure that the expert understands and 1119 accepts his or her responsibilities, or appoint a new expert. 1121 o The designated expert is not required to personally bear the 1122 burden of evaluating and deciding all requests, but acts as a 1123 shepherd for the request, enlisting the help of others as 1124 appropriate. In the case that a request is denied, and rejecting 1125 the request is likely to be controversial, the expert should have 1126 the support of other subject matter experts. That is, the expert 1127 must be able to defend a decision to the community as a whole. 1129 When a designated expert is used, the documentation should give clear 1130 guidance to the designated expert, laying out criteria for performing 1131 an evaluation and reasons for rejecting a request. In the case where 1132 there are no specific documented criteria, the presumption should be 1133 that a code point should be granted unless there is a compelling 1134 reason to the contrary. Possible reasons to deny a request include 1135 these: 1137 o Scarcity of code points, where the finite remaining code points 1138 should be prudently managed, or when a request for a large number 1139 of code points is made, when a single code point is the norm. 1141 o Documentation is not of sufficient clarity to evaluate or ensure 1142 interoperability. 1144 o The code point is needed for a protocol extension, but the 1145 extension is not consistent with the documented (or generally 1146 understood) architecture of the base protocol being extended, and 1147 would be harmful to the protocol if widely deployed. It is not 1148 the intent that "inconsistencies" refer to minor differences "of a 1149 personal preference nature". Instead, they refer to significant 1150 differences such as inconsistencies with the underlying security 1151 model, implying a change to the semantics of an existing message 1152 type or operation, requiring unwarranted changes in deployed 1153 systems (compared with alternate ways of achieving a similar 1154 result), etc. 1156 o The extension would cause problems with existing deployed systems. 1158 o The extension would conflict with one under active development by 1159 the IETF, and having both would harm rather than foster 1160 interoperability. 1162 When a designated expert is used, documents MUST NOT name the 1163 designated expert in the document itself; instead, any suggested 1164 names should be relayed to the appropriate Area Director at the time 1165 the document is sent to the IESG for approval. This is usually done 1166 in the document shepherd writeup. 1168 If the request should also be reviewed on a specific public mailing 1169 list, its address should be specified. 1171 5.4. Expert Reviews and the Document Lifecycle 1173 Review by the designated expert is necessarily done at a particular 1174 point in time, and represents review of a particular version of the 1175 document. Deciding when the review should take place is a question 1176 of good judgment. And while re-reviews might be done when it's 1177 acknowledged that the documentation of the registered item has 1178 changed substantially, making sure that re-review happens requires 1179 attention and care. 1181 It is possible, through carelessness, accident, inattentiveness, or 1182 even willful disregard, that changes might be made after the 1183 designated expert's review and approval that would, if the document 1184 were re-reviewed, cause the expert not to approve the registration. 1185 It is up to the IESG, with the token held by the responsible Area 1186 Director, to be alert to such situations and to recognize that such 1187 changes need to be checked. 1189 6. Well-Known Registration Status Terminology 1191 The following labels describe the status of an assignment or range of 1192 assignments: 1194 Private Use: Private use only (not assigned), as described in 1195 Section 4.1. 1197 Experimental: Available for general experimental use as described 1198 in [RFC3692]. IANA does not record specific assignments for 1199 any particular use. 1201 Unassigned: Not currently assigned, and available for assignment 1202 via documented procedures. While it's generally clear that 1203 any values that are not registered are unassigned and 1204 available for assignment, it is sometimes useful to 1205 explicitly specify that situation. Note that this is 1206 distinctly different from "Reserved". 1208 Reserved: Not assigned and not available for assignment. 1209 Reserved values are held for special uses, such as to extend 1210 the namespace when it becomes exhausted. Note that this is 1211 distinctly different from "Unassigned". 1213 Reserved values can be released for assignment by the change 1214 controller for the registry (this is often the IESG, for 1215 registries created by RFCs in the IETF stream). 1217 7. Documentation References in IANA Registries 1219 Usually, registries and registry entries include references to 1220 documentation (RFCs or other documents). The purpose of these 1221 references is to provide pointers for implementors to find details 1222 necessary for implementation, NOT to simply note what document 1223 created the registry or entry. Therefore: 1225 o If a document registers an item that is defined and explained 1226 elsewhere, the registered reference should be to that document, 1227 and not to the document that is merely performing the 1228 registration. 1230 o If the registered item is defined and explained in the current 1231 document, it is important to include sufficient information to 1232 enable implementors to understand the item and to create a proper 1233 implementation. 1235 o If the registered item is explained primarily in a specific 1236 section of the reference document, it is useful to include a 1237 section reference. For example, "[RFC9876], Section 3.2", rather 1238 than just "[RFC9876]". 1240 o For documentation of a new registry, the reference should provide 1241 information about the registry itself, not just a pointer to the 1242 creation of it. Useful information includes the purpose of the 1243 registry, a rationale for its creation, documentation of the 1244 process and policy for new registrations, guidelines for new 1245 registrants or designated experts, and other such related 1246 information. But note that, while it's important to include this 1247 information in the document, it needn't (and shouldn't) all be in 1248 the IANA Considerations section. See Section 1.1. 1250 8. What to Do in "bis" Documents 1252 On occaison, an RFC is issued that obsoletes a previous edition of 1253 the same document. We sometimes call these "bis" documents, such as 1254 when RFC 9876 is updated by draft-ietf-foo-rfc9876bis. When the 1255 original document created registries and/or registered entries, there 1256 is a question of how to handle the IANA Considerations section in the 1257 "bis" document. 1259 If the registrations specify the original document as a reference, 1260 those registrations should be updated to point to the current (not 1261 obsolete) documentation for those items. Usually, that will mean 1262 changing the reference to be the "bis" document. There will, though, 1263 be times when a document updates another, and changes the definitive 1264 reference for some items, but not for others. Be sure that the 1265 references are always set to point to the correct, current 1266 documentation for each item. 1268 For example, suppose RFC 9876 registered the "BANANA" flag in the 1269 "Fruit Access Flags" registry, and the documentation for that flag is 1270 in Section 3.2. 1272 The current registry might look, in part, like this: 1274 Name Description Reference 1275 -------- ------------------- --------- 1276 BANANA Flag for bananas [RFC9876], Section 3.2 1278 If draft-ietf-foo-rfc9876bis obsoletes RFC 9876 and, because of some 1279 rearrangement, now documents the flag in Section 4.1.2, the IANA 1280 Considerations of the bis document might contain text such as this: 1282 IANA is asked to change the registration information for the 1283 BANANA flag in the "Fruit Access Flags" registry to the following: 1285 Name Description Reference 1286 -------- ------------------- --------- 1287 BANANA Flag for bananas [[this RFC]], Section 4.2.1 1289 In many cases, if there are a number of registered references to the 1290 original RFC and the document organization has not changed the 1291 registered section numbering much, it may simply be reasonable to do 1292 this: 1294 Because this document obsoletes RFC 9876, IANA is asked to change 1295 all registration information that references [RFC9876] to instead 1296 reference [[this RFC]]. 1298 If information for registered items has been or is being moved to 1299 other documents, then, of course, the registration information should 1300 be changed to point to those other documents. In no case is it 1301 reasonable to leave documentation pointers to the obsoleted document 1302 for any registries or registered items that are still in current use. 1304 9. Miscellaneous Issues 1306 9.1. When There Are No IANA Actions 1308 Before an Internet-Draft can be published as an RFC, IANA needs to 1309 know what actions (if any) it needs to perform. Experience has shown 1310 that it is not always immediately obvious whether a document has no 1311 IANA actions, without reviewing the document in some detail. In 1312 order to make it clear to IANA that it has no actions to perform (and 1313 that the author has consciously made such a determination), such 1314 documents should include an IANA Considerations section that states: 1316 This document has no IANA actions. 1318 This statement, or an equivalent, must only be inserted after the 1319 working group or individual submitter has carefully verified it to be 1320 true. Using such wording as a matter of "boilerplate" or without 1321 careful consideration can lead to incomplete or incorrect IANA 1322 actions being performed. 1324 If a specification makes use of values from a namespace in which 1325 assignments are not made by IANA, it may be useful to note this fact, 1326 with wording such as this: 1328 The values of the Foobar parameter are assigned by the Barfoo 1329 registry on behalf of the Rabfoo Forum. Therefore, this document 1330 has no IANA actions. 1332 In some cases, the absence of IANA-assigned values may be considered 1333 valuable information for future readers; in other cases, it may be 1334 considered of no value once the document has been approved, and may 1335 be removed before archival publication. This choice should be made 1336 clear in the draft, for example, by including a sentence such as 1338 [RFC Editor: please remove this section prior to publication.] 1340 or 1342 [RFC Editor: please do not remove this section.] 1344 9.2. Namespaces Lacking Documented Guidance 1346 For all existing RFCs that either explicitly or implicitly rely on 1347 IANA to make assignments without specifying a precise assignment 1348 policy, IANA (in consultation with the IESG) will continue to decide 1349 what policy is appropriate. Changes to existing policies can always 1350 be initiated through the normal IETF consensus process. 1352 All future RFCs that either explicitly or implicitly rely on IANA to 1353 register or otherwise administer namespace assignments MUST provide 1354 guidelines for administration of the namespace. 1356 9.3. After-the-Fact Registrations 1358 Occasionally, the IETF becomes aware that an unassigned value from a 1359 namespace is in use on the Internet or that an assigned value is 1360 being used for a different purpose than it was registered for. The 1361 IETF does not condone such misuse; procedures of the type described 1362 in this document MUST be applied to such cases. In the absence of 1363 specifications to the contrary, values may only be reassigned for a 1364 different purpose with the consent of the original assignee (when 1365 possible) and with due consideration of the impact of such a 1366 reassignment. In cases of likely controversy, consultation with the 1367 IESG is advised. 1369 9.4. Reclaiming Assigned Values 1371 Reclaiming previously assigned values for reuse is tricky, because 1372 doing so can lead to interoperability problems with deployed systems 1373 still using the assigned values. Moreover, it can be extremely 1374 difficult to determine the extent of deployment of systems making use 1375 of a particular value. However, in cases where the namespace is 1376 running out of unassigned values and additional ones are needed, it 1377 may be desirable to attempt to reclaim unused values. When 1378 reclaiming unused values, the following (at a minimum) should be 1379 considered: 1381 o Attempts should be made to contact the original party to which a 1382 value is assigned, to determine if the value was ever used, and if 1383 so, the extent of deployment. (In some cases, products were never 1384 shipped or have long ceased being used. In other cases, it may be 1385 known that a value was never actually used at all.) 1387 o Reassignments should not normally be made without the concurrence 1388 of the original requester. Reclamation under such conditions 1389 should only take place where there is strong evidence that a value 1390 is not widely used, and the need to reclaim the value outweighs 1391 the cost of a hostile reclamation. In any case, IESG Approval is 1392 needed in this case. 1394 o It may be appropriate to write up the proposed action and solicit 1395 comments from relevant user communities. In some cases, it may be 1396 appropriate to write an RFC that goes through a formal IETF 1397 process (including IETF Last Call) as was done when DHCP reclaimed 1398 some of its "Private Use" options [RFC3942]. 1400 9.5. Contact Person vs Assignee or Owner 1402 Many registries include designation of a technical or administrative 1403 contact associated with each entry. Often, this is recorded as 1404 contact information for an individual. It is unclear, though, what 1405 role the individual has with respect to the registration: is this 1406 item registered on behalf of the individual, the company the 1407 individual worked for, or perhaps another organization the individual 1408 was acting for? 1410 This matters because some time later, when the individual has changed 1411 jobs or roles, and perhaps can no longer be contacted, someone might 1412 want to update the registration. IANA has no way to know what 1413 company, organization, or individual should be allowed to take the 1414 registration over. For registrations rooted in RFCs, the stream 1415 owner (such as the IESG or the IAB) can make an overriding decision. 1416 But in other cases, there is no recourse. 1418 Registries can include, in addition to a "Contact" field, an 1419 "Assignee" or "Owner" field that can be used to address this 1420 situation, giving IANA clear guidance as to the actual owner of the 1421 registration. Alternatively, organizations can put an organizational 1422 role into the "Contact" field in order to make their ownership clear. 1424 9.6. Closing or Obsoleting a Registry 1426 Sometimes there is a request to "close" a registry to further 1427 registrations. When a registry is closed, no further registrations 1428 will be accepted. The information in the registry will still be 1429 valid and registrations already in the registry can still be updated. 1431 A closed registry can also be marked as "obsolete", as an indication 1432 that the information in the registry is no longer in current use. 1434 Specific entries in a registry can be marked as "obsolete" (no longer 1435 in use) or "deprecated" (use is not recommended). 1437 Such changes to registries and registered values are subject to 1438 normal change controls (see Section 2.3.3). Any closure, 1439 obsolescence, or deprecation serves to annotate the registry 1440 involved; the information in the registry remains there for 1441 informational and historic purposes. 1443 10. Appeals 1445 Appeals of protocol parameter registration decisions can be made 1446 using the normal IETF appeals process as described in [RFC2026], 1447 Section 6.5. That is, an initial appeal should be directed to the 1448 IESG, followed (if necessary) by an appeal to the IAB. 1450 11. Mailing Lists 1452 All IETF mailing lists associated with evaluating or discussing 1453 assignment requests as described in this document are subject to 1454 whatever rules of conduct and methods of list management are 1455 currently defined by Best Current Practices or by IESG decision. 1457 12. Security Considerations 1459 Information that creates or updates a registration needs to be 1460 authenticated and authorized. IANA updates registries according to 1461 instructions in published RFCs and from the IESG. It also may accept 1462 clarifications from document authors, relevant working group chairs, 1463 Designated Experts, and mail list participants, too. 1465 Information concerning possible security vulnerabilities of a 1466 protocol may change over time. Likewise, security vulnerabilities 1467 related to how an assigned number is used may change as well. As new 1468 vulnerabilities are discovered, information about such 1469 vulnerabilities may need to be attached to existing registrations, so 1470 that users are not misled as to the true security issues surrounding 1471 the use of a registered number. 1473 An analysis of security issues is generally required for all 1474 protocols that make use of parameters (data types, operation codes, 1475 keywords, etc.) used in IETF protocols or registered by IANA. Such 1476 security considerations are usually included in the protocol document 1477 [RFC3552]. It is the responsibility of the IANA considerations 1478 associated with a particular registry to specify what (if any) 1479 security considerations must be provided when assigning new values, 1480 and the process for reviewing such claims. 1482 13. Changes Relative to Earlier Editions of BCP 26 1484 13.1. 2013: Changes in This Document Relative to RFC 5226 1486 Significant additions: 1488 o Added Section 1.1, Keep IANA Considerations for IANA 1490 o Added Section 1.2, For More Information 1492 o Added Section 2.1, Hierarchical Registry Structure 1493 o Added Section 2.3, Best Practice for Selecting an Appropriate 1494 Policy. 1496 o Added Section 2.3.2, Using Multiple Policies in Combination. 1498 o Added Section 2.3.3, Specifying Change Control for a Registry 1500 o Added Section 3.4, Early Allocations 1502 o Moved well-known policies into a separate section for each, 1503 subsections of Section 4. 1505 o Added Section 5.4, Expert Reviews and the Document Lifecycle 1507 o Added Section 7, Documentation References in IANA Registries 1509 o Added Section 8, What to Do in "bis" Documents 1511 o Added Section 9.5, Contact Person vs Assignee or Owner 1513 o Added Section 9.6, Closing or Obsoleting a Registry 1515 Clarifications and such: 1517 o Some reorganization -- moved text around for clarity and easier 1518 reading. 1520 o Made clarifications about identification of IANA registries and 1521 use of URLs for them. 1523 o Clarified the distinction between "Unassigned" and "Reserved". 1525 o Made some clarifications in "Expert Review" about instructions to 1526 the designated expert. 1528 o Made some clarifications in "Specification Required" about how to 1529 declare this policy. 1531 o Assorted minor clarifications and editorial changes throughout. 1533 13.2. 2008: Changes in RFC 5226 Relative to RFC 2434 1535 Changes include: 1537 o Major reordering of text to expand descriptions and to better 1538 group topics such as "updating registries" vs. "creating new 1539 registries", in order to make it easier for authors to find the 1540 text most applicable to their needs. 1542 o Numerous editorial changes to improve readability. 1544 o Changed the term "IETF Consensus" to "IETF Review" and added more 1545 clarifications. History has shown that people see the words "IETF 1546 Consensus" (without consulting the actual definition) and are 1547 quick to make incorrect assumptions about what the term means in 1548 the context of IANA Considerations. 1550 o Added "RFC Required" to list of defined policies. 1552 o Much more explicit directions and examples of "what to put in 1553 RFCs". 1555 o "Specification Required" now implies use of a Designated Expert to 1556 evaluate specs for sufficient clarity. 1558 o Significantly changed the wording in the Designated Experts 1559 section. Main purpose is to make clear that Expert Reviewers are 1560 accountable to the community, and to provide some guidance for 1561 review criteria in the default case. 1563 o Changed wording to remove any special appeals path. The normal 1564 RFC 2026 appeals path is used. 1566 o Added a section about reclaiming unused value. 1568 o Added a section on after-the-fact registrations. 1570 o Added a section indicating that mailing lists used to evaluate 1571 possible assignments (such as by a Designated Expert) are subject 1572 to normal IETF rules. 1574 14. Acknowledgments 1576 14.1. Acknowledgments for This Document (2013) 1578 Thomas Narten and Harald Tveit Alvestrand edited the two earlier 1579 editions of this document (RFCs 2434 and 5226), and Thomas continues 1580 his role in this third edition. Much of the text from RFC 5226 1581 remains in this edition. 1583 This document has benefited from thorough review and comments by John 1584 Klensin and Mark Nottingham. 1586 Special thanks to Mark Nottingham for reorganizing some of the text 1587 for better organization and readability. 1589 14.2. Acknowledgments from the second edition (2008) 1591 The original acknowledgments section in RFC 5226 was: 1593 This document has benefited from specific feedback from Jari Arkko, 1594 Marcelo Bagnulo Braun, Brian Carpenter, Michelle Cotton, Spencer 1595 Dawkins, Barbara Denny, Miguel Garcia, Paul Hoffman, Russ Housley, 1596 John Klensin, Allison Mankin, Blake Ramsdell, Mark Townsley, Magnus 1597 Westerlund, and Bert Wijnen. 1599 14.3. Acknowledgments from the first edition (1998) 1601 The original acknowledgments section in RFC 2434 was: 1603 Jon Postel and Joyce Reynolds provided a detailed explanation on what 1604 IANA needs in order to manage assignments efficiently, and patiently 1605 provided comments on multiple versions of this document. Brian 1606 Carpenter provided helpful comments on earlier versions of the 1607 document. One paragraph in the Security Considerations section was 1608 borrowed from [RFC4288]. 1610 15. References 1612 15.1. Normative References 1614 [RFC2026] Bradner, S., "The Internet Standards Process -- Revision 1615 3", BCP 9, RFC 2026, October 1996. 1617 [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate 1618 Requirement Levels", BCP 14, RFC 2119, March 1997. 1620 15.2. Informative References 1622 [I-D.cotton-rfc4020bis] 1623 Cotton, M., "Early IANA Allocation of Standards Track Code 1624 Points", draft-cotton-rfc4020bis-02 (work in progress), 1625 October 2013. 1627 [RFC0791] Postel, J., "Internet Protocol", STD 5, RFC 791, September 1628 1981. 1630 [RFC2860] Carpenter, B., Baker, F., and M. Roberts, "Memorandum of 1631 Understanding Concerning the Technical Work of the 1632 Internet Assigned Numbers Authority", RFC 2860, June 2000. 1634 [RFC2939] Droms, R., "Procedures and IANA Guidelines for Definition 1635 of New DHCP Options and Message Types", BCP 43, RFC 2939, 1636 September 2000. 1638 [RFC3228] Fenner, B., "IANA Considerations for IPv4 Internet Group 1639 Management Protocol (IGMP)", BCP 57, RFC 3228, February 1640 2002. 1642 [RFC3552] Rescorla, E. and B. Korver, "Guidelines for Writing RFC 1643 Text on Security Considerations", BCP 72, RFC 3552, July 1644 2003. 1646 [RFC3575] Aboba, B., "IANA Considerations for RADIUS (Remote 1647 Authentication Dial In User Service)", RFC 3575, July 1648 2003. 1650 [RFC3692] Narten, T., "Assigning Experimental and Testing Numbers 1651 Considered Useful", BCP 82, RFC 3692, January 2004. 1653 [RFC3748] Aboba, B., Blunk, L., Vollbrecht, J., Carlson, J., and H. 1654 Levkowetz, "Extensible Authentication Protocol (EAP)", RFC 1655 3748, June 2004. 1657 [RFC3942] Volz, B., "Reclassifying Dynamic Host Configuration 1658 Protocol version 4 (DHCPv4) Options", RFC 3942, November 1659 2004. 1661 [RFC3968] Camarillo, G., "The Internet Assigned Number Authority 1662 (IANA) Header Field Parameter Registry for the Session 1663 Initiation Protocol (SIP)", BCP 98, RFC 3968, December 1664 2004. 1666 [RFC4005] Calhoun, P., Zorn, G., Spence, D., and D. Mitton, 1667 "Diameter Network Access Server Application", RFC 4005, 1668 August 2005. 1670 [RFC4025] Richardson, M., "A Method for Storing IPsec Keying 1671 Material in DNS", RFC 4025, March 2005. 1673 [RFC4044] McCloghrie, K., "Fibre Channel Management MIB", RFC 4044, 1674 May 2005. 1676 [RFC4124] Le Faucheur, F., "Protocol Extensions for Support of 1677 Diffserv-aware MPLS Traffic Engineering", RFC 4124, June 1678 2005. 1680 [RFC4169] Torvinen, V., Arkko, J., and M. Naslund, "Hypertext 1681 Transfer Protocol (HTTP) Digest Authentication Using 1682 Authentication and Key Agreement (AKA) Version-2", RFC 1683 4169, November 2005. 1685 [RFC4271] Rekhter, Y., Li, T., and S. Hares, "A Border Gateway 1686 Protocol 4 (BGP-4)", RFC 4271, January 2006. 1688 [RFC4283] Patel, A., Leung, K., Khalil, M., Akhtar, H., and K. 1689 Chowdhury, "Mobile Node Identifier Option for Mobile IPv6 1690 (MIPv6)", RFC 4283, November 2005. 1692 [RFC4288] Freed, N. and J. Klensin, "Media Type Specifications and 1693 Registration Procedures", RFC 4288, December 2005. 1695 [RFC4340] Kohler, E., Handley, M., and S. Floyd, "Datagram 1696 Congestion Control Protocol (DCCP)", RFC 4340, March 2006. 1698 [RFC4395] Hansen, T., Hardie, T., and L. Masinter, "Guidelines and 1699 Registration Procedures for New URI Schemes", BCP 35, RFC 1700 4395, February 2006. 1702 [RFC4422] Melnikov, A. and K. Zeilenga, "Simple Authentication and 1703 Security Layer (SASL)", RFC 4422, June 2006. 1705 [RFC4446] Martini, L., "IANA Allocations for Pseudowire Edge to Edge 1706 Emulation (PWE3)", BCP 116, RFC 4446, April 2006. 1708 [RFC4520] Zeilenga, K., "Internet Assigned Numbers Authority (IANA) 1709 Considerations for the Lightweight Directory Access 1710 Protocol (LDAP)", BCP 64, RFC 4520, June 2006. 1712 [RFC4589] Schulzrinne, H. and H. Tschofenig, "Location Types 1713 Registry", RFC 4589, July 2006. 1715 [RFC4727] Fenner, B., "Experimental Values In IPv4, IPv6, ICMPv4, 1716 ICMPv6, UDP, and TCP Headers", RFC 4727, November 2006. 1718 [RFC5246] Dierks, T. and E. Rescorla, "The Transport Layer Security 1719 (TLS) Protocol Version 1.2", RFC 5246, August 2008. 1721 [RFC5378] Bradner, S. and J. Contreras, "Rights Contributors Provide 1722 to the IETF Trust", BCP 78, RFC 5378, November 2008. 1724 [RFC5742] Alvestrand, H. and R. Housley, "IESG Procedures for 1725 Handling of Independent and IRTF Stream Submissions", BCP 1726 92, RFC 5742, December 2009. 1728 [RFC5771] Cotton, M., Vegoda, L., and D. Meyer, "IANA Guidelines for 1729 IPv4 Multicast Address Assignments", BCP 51, RFC 5771, 1730 March 2010. 1732 [RFC5795] Sandlund, K., Pelletier, G., and L-E. Jonsson, "The RObust 1733 Header Compression (ROHC) Framework", RFC 5795, March 1734 2010. 1736 [RFC6195] Eastlake, D., "Domain Name System (DNS) IANA 1737 Considerations", RFC 6195, March 2011. 1739 [RFC6275] Perkins, C., Johnson, D., and J. Arkko, "Mobility Support 1740 in IPv6", RFC 6275, July 2011. 1742 [RFC6709] Carpenter, B., Aboba, B., and S. Cheshire, "Design 1743 Considerations for Protocol Extensions", RFC 6709, 1744 September 2012. 1746 Authors' Addresses 1748 Michelle Cotton 1749 Internet Corporation for Assigned Names and Numbers 1750 12025 Waterfront Drive, Suite 300 1751 Los Angeles, CA 90094-2536 1752 US 1754 Phone: +1 310 823 9358 1755 Email: michelle.cotton@icann.org 1756 URI: http://www.icann.org/ 1758 Barry Leiba 1759 Huawei Technologies 1761 Phone: +1 646 827 0648 1762 Email: barryleiba@computer.org 1763 URI: http://internetmessagingtechnology.org/ 1765 Thomas Narten 1766 IBM Corporation 1767 3039 Cornwallis Ave., PO Box 12195 - BRQA/502 1768 Research Triangle Park, NC 27709-2195 1769 US 1771 Phone: +1 919 254 7798 1772 Email: narten@us.ibm.com