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Hoffman 5 Expires: July 25, 2013 VPN Consortium 6 January 21, 2013 8 Variants in Second-Level Names Registered in Top Level Domains 9 draft-levine-tld-variant-06 11 Abstract 13 Internationalized Domain Names for Applications (IDNA) provides a 14 method to map a subset of names written in Unicode into the DNS. 15 Because of Unicode decisions, appearance, language and writing system 16 conventions, and historical reasons, it often has been asserted that 17 there is more than one way to write what competent readers and 18 writers think of as the same host name; the different ways of writing 19 are often called "variants". (The authors note that there are many 20 conflicting definitions for the term "variant" in the IDNA 21 community.) This document surveys the approaches that top level 22 domains have taken to the registration and provisioning of domain 23 names that have variants. This document is not a product of the 24 IETF, does not propose any method to make variants work "correctly", 25 and is not an introduction to internationalization or IDNA. 27 Status of This Memo 29 This Internet-Draft is submitted in full conformance with the 30 provisions of BCP 78 and BCP 79. 32 Internet-Drafts are working documents of the Internet Engineering 33 Task Force (IETF). Note that other groups may also distribute 34 working documents as Internet-Drafts. The list of current Internet- 35 Drafts is at http://datatracker.ietf.org/drafts/current/. 37 Internet-Drafts are draft documents valid for a maximum of six months 38 and may be updated, replaced, or obsoleted by other documents at any 39 time. It is inappropriate to use Internet-Drafts as reference 40 material or to cite them other than as "work in progress." 42 This Internet-Draft will expire on July 25, 2013. 44 Copyright Notice 46 Copyright (c) 2013 IETF Trust and the persons identified as the 47 document authors. All rights reserved. 49 This document is subject to BCP 78 and the IETF Trust's Legal 50 Provisions Relating to IETF Documents 51 (http://trustee.ietf.org/license-info) in effect on the date of 52 publication of this document. Please review these documents 53 carefully, as they describe your rights and restrictions with respect 54 to this document. Code Components extracted from this document must 55 include Simplified BSD License text as described in Section 4.e of 56 the Trust Legal Provisions and are provided without warranty as 57 described in the Simplified BSD License. 59 Table of Contents 61 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 3 62 2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 4 63 3. Base Documents . . . . . . . . . . . . . . . . . . . . . . . 5 64 4. Domain Practices of gTLDs . . . . . . . . . . . . . . . . . . 5 65 4.1. AERO . . . . . . . . . . . . . . . . . . . . . . . . . . 5 66 4.2. ASIA . . . . . . . . . . . . . . . . . . . . . . . . . . 6 67 4.3. BIZ . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 68 4.4. CAT . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 69 4.5. COM . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 70 4.6. COOP . . . . . . . . . . . . . . . . . . . . . . . . . . 7 71 4.7. INFO . . . . . . . . . . . . . . . . . . . . . . . . . . 7 72 4.8. JOBS . . . . . . . . . . . . . . . . . . . . . . . . . . 7 73 4.9. MOBI . . . . . . . . . . . . . . . . . . . . . . . . . . 7 74 4.10. MUSEUM . . . . . . . . . . . . . . . . . . . . . . . . . 7 75 4.11. NAME . . . . . . . . . . . . . . . . . . . . . . . . . . 8 76 4.12. NET . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 77 4.13. ORG . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 78 4.14. POST . . . . . . . . . . . . . . . . . . . . . . . . . . 8 79 4.15. PRO . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 80 4.16. TEL . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 81 4.17. TRAVEL . . . . . . . . . . . . . . . . . . . . . . . . . 9 82 4.18. XXX . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 83 5. Domain Practices of ccTLDs . . . . . . . . . . . . . . . . . 9 84 5.1. BG . . . . . . . . . . . . . . . . . . . . . . . . . . . 10 85 5.2. BR . . . . . . . . . . . . . . . . . . . . . . . . . . . 10 86 5.3. CL . . . . . . . . . . . . . . . . . . . . . . . . . . . 10 87 5.4. CN . . . . . . . . . . . . . . . . . . . . . . . . . . . 10 88 5.5. ES . . . . . . . . . . . . . . . . . . . . . . . . . . . 10 89 5.6. EU . . . . . . . . . . . . . . . . . . . . . . . . . . . 10 90 5.7. GR . . . . . . . . . . . . . . . . . . . . . . . . . . . 11 91 5.8. IL . . . . . . . . . . . . . . . . . . . . . . . . . . . 11 92 5.9. IR . . . . . . . . . . . . . . . . . . . . . . . . . . . 11 93 5.10. JP . . . . . . . . . . . . . . . . . . . . . . . . . . . 11 94 5.11. KR . . . . . . . . . . . . . . . . . . . . . . . . . . . 11 95 5.12. MY . . . . . . . . . . . . . . . . . . . . . . . . . . . 11 96 5.13. NZ . . . . . . . . . . . . . . . . . . . . . . . . . . . 11 97 5.14. PL . . . . . . . . . . . . . . . . . . . . . . . . . . . 12 98 5.15. RS . . . . . . . . . . . . . . . . . . . . . . . . . . . 12 99 5.16. RU . . . . . . . . . . . . . . . . . . . . . . . . . . . 12 100 5.17. SA . . . . . . . . . . . . . . . . . . . . . . . . . . . 12 101 5.18. SE . . . . . . . . . . . . . . . . . . . . . . . . . . . 12 102 5.19. TW . . . . . . . . . . . . . . . . . . . . . . . . . . . 12 103 5.20. UA . . . . . . . . . . . . . . . . . . . . . . . . . . . 12 104 5.21. VE . . . . . . . . . . . . . . . . . . . . . . . . . . . 13 105 5.22. XN--90A3AC . . . . . . . . . . . . . . . . . . . . . . . 13 106 5.23. XN--MGBERP4A5D4AR . . . . . . . . . . . . . . . . . . . . 13 107 6. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 13 108 7. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 13 109 8. Security Considerations . . . . . . . . . . . . . . . . . . . 13 110 9. References . . . . . . . . . . . . . . . . . . . . . . . . . 13 111 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 18 113 1. Introduction 115 Internationalized Domain Names for Applications (IDNA) [RFC5890] 116 allows host names in the DNS [RFC1035] to contain characters from the 117 Unicode repertoire. Some Unicode characters are considered to be 118 "variants" of one another. Because of the 20th century reform of 119 Chinese writing, there is often more than one representation of what 120 Chinese speakers think of as the same character. Some languages 121 written in Latin characters with accents and diacritical marks, known 122 as decorated characters, allow the decorations to be omitted in some 123 situations; for example, French sometimes omits accents on capital 124 letters, depending on country and culture. Due to the difficulty of 125 representing decorated characters in ASCII systems, many users have 126 informally used undecorated characters in DNS host names, even when 127 they are not linguistically equivalent to the decorated versions. 129 There is no single agreed-on definition of "variant". In IDN Variant 130 TLDs [VARIANTTLDS], ICANN says that variants "occur when a single 131 conceptual character can be identified with two or more different 132 Unicode Code Points with graphic representations that may be visually 133 similar". In ICANN's IDN Variant Issues Project report [VIPREPORT], 134 it says in part "There is today no fully accepted definition for what 135 may constitute a variant relationship between top-level labels". RFC 136 3743 [RFC3743] (an Informational RFC, not the product of the IETF), 137 say that the idea of variants is "wherein one conceptual character 138 can be identified with several different Code Points in character 139 sets for computer use". 141 The proper handing of variant names has been a topic of extensive 142 debate and research, with little consensus reached on how to handle 143 them, or even what characters are variants of each other. Many 144 people would like variant names to behave "the same", for a diverse 145 range of meanings of "same." In some cases it is a textual 146 similarity, such as variants having corresponding DNS records, in 147 some it is functional similarity, such as variant names resolving to 148 the same web server, while in others it is user experience 149 similarity, such as names resolving to web sites which while not 150 identical are perceived by human users as equivalent. 152 This document provides a snapshot of variant handling in the top 153 level domains contracted by ICANN, so-called gTLDs (generic TLDs) and 154 sTLDs (sponsored TLDs), as of late 2012. We chose those domains 155 because ICANN requires each TLD to describe its IDN and variant 156 practices, and the TLD zone files are available for inspection, to 157 verify what actually goes into the zones. This document also 158 contains a small sampling of so-called ccTLDs (country code TLDs, the 159 TLDs that consist of two ASCII letters) for which we could find 160 information. 162 Since "variant" can mean vastly different things to different people, 163 there is also no agreement about when two zones are supposed to 164 "behave the same". Also, the gTLDs and sTLDs might have different 165 views of what variants are and are not required to report to ICANN 166 about their policies. 168 2. Terminology 170 We use some terminology that has become generally agreed to when 171 discussing variant names, although we openly admit that such 172 agreement is not complete, and the terminology continues to change. 174 Bundle: The IDN practices documents (see below) can identify sets of 175 code points that are considered variants of each other using 176 Language Variant Tables, defined in [RFC3743]. A set of names in 177 which the characters in each position are variants is known as a 178 bundle, or more technically as an "IDL Package". The variant 179 rules vary among languages, and for the same language can vary 180 among TLDs. Many languages do not define variant characters, and 181 hence do not have bundles. 183 Allocated: A name is allocated if sponsorship of that label in some 184 zone has been granted. This is similar to what many people refer 185 to as "registered". 187 Active: A name is active if it appears as an owner name in a zone. 188 Most allocated names are active, but some are not. 190 Blocked: Some names cannot be registered at all. For example, some 191 registries allow one name in a bundle to be registered, and block 192 the rest. 194 Withheld: Some names can only be allocated under certain conditions. 195 For example, some registries permit only the registrant of one 196 name in a bundle to register or activate other names in the same 197 bundle. 199 Parallel NS: Multiple names in a bundle are provisioned in the TLD 200 with identical NS records, so they all are handled by the same 201 name servers. 203 DNAME aliasing: The DNAME [RFC6672] DNS record creates a shadow tree 204 of DNS records, roughly as though there were a CNAME in the shadow 205 tree pointing to each name in the target tree. DNAMEs have been 206 used both to provide resolution for several names in a bundle, and 207 to provide resolution for every name under a TLD. 209 3. Base Documents 211 ICANN has published a variety of documents on variant management. 212 The most important are the "Guidelines for the Implementation of 213 Internationalized Domain Names" issued in Version 1.0 [G1] and 214 Version 3.0 [G3]. 216 ICANN says that TLDs are supposed to register an IDN practices 217 document with IANA for each language and/or script in which the TLD 218 accepts IDN registrations, to be entered in the IANA Repository of 219 IDN Practices [IANAIDN]. The practices document lists the Unicode 220 characters allowed in names in the language or script, which 221 characters are considered equivalent, and which of an equivalent 222 group is preferred. Some TLDs have been more diligent than others at 223 keeping the registry up to date. Also, some TLDs have tables for a 224 few languages and scripts, while others (notably .COM, .NET, and 225 .NAME) have a large set of tables, including some for languages and 226 scripts that are no longer spoken or used, such as Runic and Ogham. 227 The authors also note that many of the tables in the IANA registry 228 are clearly out of date, containing URLs of policy pages that no 229 longer exist and contact information for people who have left the 230 registry. 232 Some of the ICANN agreements with each TLD [ICANNAGREE] describe the 233 TLD's IDN practices, but most don't. 235 4. Domain Practices of gTLDs 237 This list covers the most of the current set of gTLDs. In most 238 cases, the authors have also checked the zone files for the gTLD to 239 verify or augment the policy description. 241 4.1. AERO 242 The .AERO TLD has no IDNs, and no rules or practices for them. 244 4.2. ASIA 246 The .ASIA domain accepts registrations in many Asian languages. They 247 have IANA tables for Japanese, Korean, and Chinese. The IANA tables 248 refer to their CJK IDN policies [ASIACJK], which say that applied-for 249 and preferred IDN variants are "active and included in the zone." No 250 IDN publication mechanism is described in the documentation, but 251 since the zone file contains no DNAMEs, they must be using parallel 252 NS for variants. 254 4.3. BIZ 256 ICANN gave the registry (Neustar) non-specific permission to register 257 IDNs in a letter in 2004 [TWOMEY04A]. The IDN rules were apparently 258 discussed with ICANN, but not defined; see Appendix 9 of the registry 259 agreement [ICANNBIZ9]. 261 They have about a dozen IANA tables. No IDN publication mechanism is 262 described, but from inspection it appears that variants are blocked. 264 4.4. CAT 266 The IDN rules are described in Appendix S Part VII.2 [ICANNCATS] of 267 the ICANN agreement. "Registry will take a very cautious approach in 268 its IDN offerings. IDNs will be bundled with the equivalent ASCII 269 domains." The only language is Catalan. No IDN publication 270 mechanism is described. 272 Appendix S includes "The list of non-ASCII-characters for Catalan 273 language and their ASCII equivalent for the purposes of the defined 274 service" which implicitly describes bundles. The bundles consist of 275 names with accented and unaccented vowels, U+00E7 ("c with cedilla") 276 and a plain c, and the Catalan "ela geminada" written as two l's 277 separated by a U+00B7 ("middle dot") and the three characters "l-l". 279 When a registrant registers an IDN, the registry also includes the 280 ASCII version. From inspection of the zone file, the ASCII version 281 is provisioned with NS, and the IDN is a DNAME alias of the ASCII 282 version. 284 4.5. COM 286 ICANN and Verisign have extensive correspondence about IDNs and 287 variants, including letters to ICANN from Ben Turner [TURNER03] and 288 Ed Lewis [LEWIS03]. 290 The IANA registry has tables for several dozen languages, including 291 archaic languages such as hieroglyphics and Aramaic. Verisign 292 publishes documents describing Scripts and Languages [VRSNLANG], 293 Character Variants [VRSNCHAR], Registration Rules [VRSNRULES], and 294 additional registration logic [VRSNADDL]. 296 In Chinese, variants are blocked (see [VRSNADDL]). In other 297 languages there is no bundling or blocking. 299 4.6. COOP 301 The .COOP TLD has no IDNs, and no rules or practices for them. 303 4.7. INFO 305 The IANA registry has a table for German. The German table notes 306 that "the Eszet ... character used in the German script will be 307 mapped to a double s string (i.e. ss)." The domain also offers 308 names in Greek, Russian, Arabic, Korean, and other languages. The 309 list and IDN tables are onthe registry's web site [INFOTABLES]. 311 Afilias says (not in a published policy) that it does not allow 312 Korean characters with different widths, and that there are no 313 variants in .INFO. 315 The registry agreement Appendix 9 [ICANNINFO9] refers to a 2003 316 letter from Paul Twomey [TWOMEY03] that refers to blocking variants. 318 4.8. JOBS 320 The .JOBS TLD has no IDNs, and no rules or practices for them. 322 4.9. MOBI 324 The zone file has about 22,000 IDNs. Afilias says (not in a 325 published policy) that .MOBI supports Simplified Chinese only and 326 that the language table for this is the same as that used by .CN. 327 Variant characters are blocked from registration. The domain has no 328 tables at IANA. The registry agreement Appendix S [ICANNMOBIS] says 329 that IDNs are provisioned according to [G1]. 331 4.10. MUSEUM 333 The zone file has many IDNs, but spot checks find that many are lame 334 or dead. A 2004 letter from Paul Twomey [TWOMEY04] refers to [G1]. 336 The registry has a detailed policy page [MUSEUMPOLICY]. IDNs are 337 accepted in Latin and Hebrew scripts, with plans for Arabic, Chinese, 338 Japanese, Korean, Cyrillic, and Greek. They do no bundling or 339 blocking, but names that may be confusable due to visual similarity 340 are not allowed, apparently determined by manual inspection, which is 341 practical due to the very small size of the domain. 343 4.11. NAME 345 The NAME TLD is managed the same as .COM. 347 4.12. NET 349 The NET TLD is managed the same as .COM. 351 4.13. ORG 353 A 2003 letter from Paul Twomey [TWOMEY03A] refers to [G1]. The 354 registry has a list of IDN languages [PIRIDN], several written in 355 Latin script, plus Chinese and Korean. A Questions page [PIRFAQ] 356 states that Chinese names have been accepted since January 2010, and 357 Cyrillic names in seven languages since February 2011. The practices 358 for some but not all of the Latin languages all are registered with 359 IANA. 361 A Chinese language policy form on the PIR web site says that the ZH- 362 CN and ZH-TW IDNs use the corresponding ccTLD tables from IANA, and 363 check boxes say that Variant Registration Polices and Variant 364 Management Policies are applicable, but don't say what those policies 365 are. 367 Private correspondence [CHANDIWALA12] describes not-yet-public rules 368 for variants in Chinese and Cyrillic in .ORG that restrict the number 369 of variants that a registration can have. 371 The Korean language policy form says it uses the KRNIC table for 372 Korean from IANA, that there are no variants. 374 4.14. POST 376 The .POST TLD appears to have no registrations at all yet. 378 4.15. PRO 380 The .PRO TLD has no IDNs, and no rules or practices for them. 382 4.16. TEL 384 The zone has many IDNs. It is probably operating according to a 2004 385 letter from Paul Twomey [TWOMEY04A] to Neustar which did not mention 386 specific TLDs. Its policy page [TELPOLICY] has links to IDN 387 practices for 17 languages, all but one of which are registered with 388 IANA. None of the Latin scripts do bundling or blocking. The 389 Japanese practices say that variants are blocked. The Chinese 390 practices document says: 392 Therefore, in addition to the blocking mechanism, bundling is also 393 implemented for the Chinese language IDNs. When registering a 394 Chinese language IDN (primary domain name) up to two additional 395 variant domain names will be automatically registered. The first 396 variant will consist entirely of simplified Chinese characters 397 that correspond to those comprising the primary domain name. The 398 second variant will consist exclusively of traditional Chinese 399 characters that correspond to those comprising the primary domain 400 name. 402 The primary domain name together with the requested variants 403 constitutes a bundle on which all operations are atomic. For 404 example, if the registrant adds a name server to the primary 405 domain name, all names in the bundle will be associated with that 406 new name server. 408 The zone has no DNAME records, so the second paragraph strongly 409 suggests parallel NS. 411 The .TEL TLD, intended as an online directory, does not allow 412 registrants to enter arbitrary RR's in the zone. Nearly all names 413 have NS records pointing to Telnic's own name servers. The A records 414 all point to Telnic's own web server that shows directory 415 information. NAPTR records provide the telephone number of 416 registrants for whom they have one. Users can only directly 417 provision MX records. Except that there are 16 domains, none of 418 which are IDNs, that point to random other name servers and mostly 419 appear to be parked. 421 4.17. TRAVEL 423 The .TRAVEL TLD has no IDNs, and no rules or practices for them. 425 4.18. XXX 427 The .XXX TLD has no IDNs, and no rules or practices for them. 429 5. Domain Practices of ccTLDs 430 Some ccTLDs publish their IDN policies. This section is a non- 431 exhaustive sampling of some of those policies. Note that few ccTLDs 432 make their zone files available, so the authors could not validate 433 the policies by looking in the zone files. 435 5.1. BG 437 The .BG TLD (for Bulgaria) publishes a policy page [BGPOLICY]. It 438 has published an IDN table for the Bulgarian and Russian languages in 439 [IANAIDN]. The policy does not mention variants. 441 5.2. BR 443 The .BR TLD (for Brazil) publishes a policy page [BRPOLICY]. It has 444 published an IDN table for the Portuguese language in [IANAIDN]. 445 Although the IDN table does not describe variants, the policy page 446 says that bundles consist of names that are the same disregarding 447 accents on vowels, cedillas on letter "c", and inserted or deleted 448 hyphens. Only the registrant of a name in a bundle can register 449 other names from the same bundle. 451 5.3. CL 453 The .CL TLD (for Chile) publishes a policy page [CLPOLICY]. It has 454 published an IDN table for the Latin script in [IANAIDN]. The policy 455 says that variants are not considered for registration. 457 5.4. CN 459 The .CN TLD (for China) publishes its policy as [RFC4713]. It has 460 published an IDN table for the Chinese laguage in [IANAIDN]. The 461 policy says that variants are "added into the zone file", presumably 462 as NS records. 464 5.5. ES 466 The .ES TLD (for Spain) publishes an IDN Area page [ESIDN]. It 467 allows ten accented vowels, U+00E7 ("c with cedilla"), U+00F1 ("n 468 with tilde"), and the Catalan "ela geminada" written as two l's 469 separated by a U+00B7 ("middle dot"). There are no published IDN 470 tables, and there appears to be no variant policy. 472 5.6. EU 474 The .EU TLD (for Europe) publishes a policy page [EUPOLICY]. It has 475 published IDN tables for three scripts in [IANAIDN]. There appears 476 to be no variant policy. 478 5.7. GR 480 The .GR TLD (for Greece) publishes a policy page [GRPOLICY] and an 481 FAQ [GRFAQ]. The policy says that all variants of name uder .GR are 482 assigned to the domain owner, with the zone pointing the NS records 483 of all the variants to the name server of the "main form" of the 484 registered name. The FAQ says that domain names in Greek characters 485 are inserted in the zone using their non-punctuated form in Punycode, 486 and that the punctuated form is associated with the non-punctuated 487 with a DNAME record. It does not publish IDN tables in [IANAIDN]. 489 5.8. IL 491 The .IL TLD (for Israel) publishes a policy page [ILPOLICY]. It has 492 published an IDN table for the Hebrew language in [IANAIDN]. There 493 is no variant policy. 495 5.9. IR 497 The .IR TLD (for Iran) publishes a policy page [IRPOLICY]. It has 498 published an IDN table for the Persian language in [IANAIDN]. The 499 IDN table says that it will block registration of variants. However, 500 the policy document says that no IDNs can be registered in .IR. 502 5.10. JP 504 The .JP TLD (for Japan) publishes a policy page [JPPOLICY]. It has 505 published an IDN table for the Japanese language in [IANAIDN]. Each 506 code point in that table defines no variants, which means there are 507 no variants in registration or resolution.. 509 5.11. KR 511 The .KR TLD (for Korea) appears to only publish its policy as an IDN 512 table for the Korean language in [IANAIDN]. The policy in that table 513 does not discuss variants. 515 5.12. MY 517 The .MY TLD (for Malaysia) appears to only publish its policy as an 518 IDN table for the Jawi language in [IANAIDN]; however, IANA lists 519 that as a table for the "Malay microlanguage". The policy in that 520 table does not discuss variants. 522 5.13. NZ 523 The .NZ TLD (for New Zealand) publishes a policy page [NZPOLICY]. It 524 has published IDN tables for the Latin script in [IANAIDN]. The 525 policy does not discuss variants. 527 5.14. PL 529 The .PL TLD (for Poland) publishes a policy page [PLPOLICY]. It has 530 published IDN tables for numerous European languages in [IANAIDN]. 531 The policy says that it will block registration of "look-alike" 532 variants. 534 5.15. RS 536 The .RS TLD (for Serbia) publishes a policy page [RSPOLICY]. It has 537 published IDN tables for the Serbian and Russian languages, and the 538 Latin script, in [IANAIDN]. The policy does not discuss variants. 540 5.16. RU 542 The .RU TLD (for Russia) appears to only publish its policy as an IDN 543 table for the Russian language in [IANAIDN]. The policy in that 544 table does not discuss variants. 546 5.17. SA 548 The .SA TLD (for Saudi Arabia) publishes a policy page [SAPOLICY]. 549 It has published an IDN table for the Arabic language in [IANAIDN]. 550 The policy permits the registration of variants, but it is not clear 551 whether others can register names with variants if the owner of a 552 name has not registered them. 554 5.18. SE 556 The .SE TLD (for Sweden) publishes a policy page [SEPOLICY]. It has 557 published IDN tables for the Swedish and Yiddish languages, and the 558 Latin script, in [IANAIDN]. The policy does not discuss variants. 560 5.19. TW 562 The .TW TLD (for Taiwan) appears to only publish its policy as an IDN 563 table for the Chinese language in [IANAIDN]. The policy in that 564 table does not discuss variants. 566 5.20. UA 568 The .UA TLD (for Ukraine) publishes a policy page [UAPOLICY]. It has 569 published an IDN table for the Cyrillic script in [IANAIDN]. The 570 policy does not discuss variants. 572 5.21. VE 574 The .VE TLD (for Venezuela) appears to only publish its policy as an 575 IDN table for the Spanish language in [IANAIDN]. The policy in that 576 table does not discuss variants. 578 5.22. XN--90A3AC 580 The .XN--90A3AC TLD (for Serbia) (U+0441 U+0440 U+0431) publishes a 581 policy page [RSIDNPOLICY]. It has published IDN tables for the 582 Cyrillic script in [IANAIDN]. The policy does not discuss variants. 584 5.23. XN--MGBERP4A5D4AR 586 The .XN--MGBERP4A5D4AR TLD (for Saudi Arabia) (U+0627 U+0644 U+0633 587 U+0639 U+0648 U+062F U+064A U+0629) appears to only publish its 588 policy as an IDN table for the Arabic script in [IANAIDN]. The 589 policy permits the registration of variants, but it is not clear 590 whether others can register names with variants if the owner of a 591 name has not registered them. 593 6. Acknowledgements 595 Many people contributed to this document, particularly Nacho Amadoz, 596 Marc Blanchet, Michelle Coon, Jordi Iparraguirre, Frederico A C 597 Neves, Vaggelis Segredakis, Doron Shikmoni, Andrew Sullivan, Dennis 598 Tan, and Joseph Yee. 600 7. IANA Considerations 602 This document discusses some of what is in an IANA registry, but 603 otherwise has no IANA considerations, so this section should be 604 removed before publication as an RFC. 606 8. Security Considerations 608 There are many potential security considerations for various methods 609 of dealing with IDN variants. However, this document is only a 610 catalog of current variant policies, not of whether or not they are 611 good or bad ideas from a security standpoint. The documents in the 612 Terminology section earlier have a little discusion of security 613 considerations for IDN variants. 615 9. References 617 [ASIACJK] DotAsia Organisation, ".ASIA CJK (Chinese Japanese Korean) 618 IDN Policies", May 2011, . 621 [BGPOLICY] 622 Register.bg, "Terms And Conditions For Domain Name 623 Registration And Support In The .Bg Zone And The Sub- 624 Zones", August 2011, . 627 [BRPOLICY] 628 Registro.br, "Domains in .br", September 2011, . 631 [CHANDIWALA12] 632 Chandiwala, S., "Letter from Sadik Chandiwala to John 633 Levine", December 2012. 635 [CLPOLICY] 636 NIC Chile, "Syntax Rules For Domain Names Under .CL", 637 August 2005, . 639 [ESIDN] Red.es, "IDN area", , . 642 [EUPOLICY] 643 EURid, ".eu Domain Name Registration Terms and 644 Conditions", December 2009, . 647 [G1] ICANN, "Guidelines for the Implementation of 648 Internationalized Domain Names, Version 1.0", , . 652 [G3] ICANN, "Guidelines for the Implementation of 653 Internationalized Domain Names, Version 3.0", , . 657 [GRFAQ] Foundation for Reaserch and Technology - Hellas, 658 "Frequently Asked Questions regarding [.gr] Domain Name 659 registrations", 2012, . 662 [GRPOLICY] 663 Foundation for Reaserch and Technology - Hellas, 664 "Regulation on Management and Assignment of [.gr] Domain 665 Names", 2012, . 668 [IANAIDN] IANA, "Repository of IDN Practices", , . 671 [ICANNAGREE] 672 ICANN, "ICANN Registry agreements", , . 675 [ICANNBIZ9] 676 ICANN, "Appendix 9 of ICANN .BIZ Registry agreement", Dec 677 2006, . 680 [ICANNCATS] 681 ICANN, "Appendix S of ICANN .CAT Registry agreement", Mar 682 2006, . 685 [ICANNINFO9] 686 ICANN, "Appendix 9 of ICANN .INFO Registry agreement", Dec 687 2006, . 690 [ICANNMOBIS] 691 ICANN, "Appendix S of ICANN .MOBI Registry agreement", Nov 692 2005, . 695 [ILPOLICY] 696 Israel Internet Association (ISOC-IL), "Rules for the 697 Allocation of Domain Names Under the Israel Country Code 698 Top Level Domain ("IL ")", August 2010, . 701 [INFOTABLES] 702 Afilias, "Internationalized Domain Names", 2006, . 705 [IRPOLICY] 706 IPM/IRNIC, "Internationalized Domain Names in IR", August 707 2010, . 709 [JPPOLICY] 710 JPRS, "Technology bylaws regarding generic domain name 711 registration JP", July 2012, . 714 [LEWIS03] Lewis, E., "Letter from Ed Lewis to Paul Twomey", Oct 715 2003, . 718 [MUSEUMPOLICY] 719 Musedoma, "Internationalized Domain Names (IDN) in .museum 720 - Policies and terms of use", Jan 2009, . 723 [NZPOLICY] 724 .nz Registry Services, "Internationalised Domain Names 725 (IDN)", July 2010, . 727 [PIRFAQ] Public Interest Registry, "Internationalized Domain Name 728 (IDN) Questions", 2010, . 731 [PIRIDN] Public Interest Registry, "Go Global", Jan 2009, . 734 [PLPOLICY] 735 NASK (PL-TLD), "Registering Internationalized Domain Names 736 under .PL", July 2012, . 739 [RFC1035] Mockapetris, P., "Domain names - implementation and 740 specification", STD 13, RFC 1035, November 1987. 742 [RFC3743] Konishi, K., Huang, K., Qian, H., and Y. Ko, "Joint 743 Engineering Team (JET) Guidelines for Internationalized 744 Domain Names (IDN) Registration and Administration for 745 Chinese, Japanese, and Korean", RFC 3743, April 2004. 747 [RFC4713] Lee, X., Mao, W., Chen, E., Hsu, N., and J. Klensin, 748 "Registration and Administration Recommendations for 749 Chinese Domain Names", RFC 4713, October 2006. 751 [RFC5890] Klensin, J., "Internationalized Domain Names for 752 Applications (IDNA): Definitions and Document Framework", 753 RFC 5890, August 2010. 755 [RFC6672] Rose, S. and W. Wijngaards, "DNAME Redirection in the 756 DNS", RFC 6672, June 2012. 758 [RSIDNPOLICY] 759 RNIDS, "Internationalized Domain Names(IDN) in xn--90a3ac 760 ccTLD", October 2011, . 763 [RSPOLICY] 764 RNIDS, "General Terms And Conditions For Registration of 765 .rs Domain Names", June 2009, . 768 [SAPOLICY] 769 Saudi Network Information Center, "Permitted Characters 770 and Symbols", December 2010, . 773 [SEPOLICY] 774 .SE (The Internet Infrastructure Foundation), 775 "Registration instructions", 2012, . 778 [TELPOLICY] 779 Telnic, ".TEL Policies", Jan 2007, . 782 [TURNER03] 783 Turner, B., "Letter from Ben Turner to Paul Twomey", Nov 784 2003, . 787 [TWOMEY03A] 788 Twomey, P., "Letter from Paul Twomey to Edward Viltz", Oct 789 2003, . 792 [TWOMEY03] 793 Twomey, P., "Letter from Paul Twomey to Ram Mohan", Aug 794 2003, . 797 [TWOMEY04A] 798 Twomey, P., "Letter from Paul Twomey to Richard Tindal", 799 July 2004, . 802 [TWOMEY04] 803 Twomey, P., "Letter from Paul Twomey to Cary Karp", Jan 804 2004, . 807 [UAPOLICY] 808 UA ccTLD, "Registration Schedule of IDN-domains", October 809 2010, . 811 [VARIANTTLDS] 812 ICANN, "IDN Variant TLDs", , . 815 [VIPREPORT] 816 ICANN, "A Study of Issues Related to the Management of IDN 817 Variant TLDs (Integrated Issues Report)", , . 821 [VRSNADDL] 822 Verisign, "Additional Logic", , . 827 [VRSNCHAR] 828 Verisign, "Character Variants", , . 833 [VRSNLANG] 834 Verisign, "Scripts and Languages", , . 839 [VRSNRULES] 840 Verisign, "Registration Rules", , . 845 Authors' Addresses 847 John Levine 848 Taughannock Networks 850 Email: standards@taugh.com 852 Paul Hoffman 853 VPN Consortium 855 Email: paul.hoffman@vpnc.org>