This is a proposal to register TIS-620 as a charset with IANA.

This charset is to be used as a MIME text/* media type.

Background

  TIS-620 is the standard Thai character set used in the Kingdom of
  Thailand. The standard was issued by the Thai Industrial Standards
  Institute (TISI), the Thai national standard body, in 1986 and re-issued
  again in 1990 without changing code-point assignment. It has been in
  widely use among Thai communities since then.

  The standard was also registered under ISO 2375 by ECMA as ISO-IR-166.
  Another attempt was made to register the same charset as ISO/IEC 8859
  Part 11. However, this did not succeed because JTC1/SC2 decided that
  charsets with non-spacing characters will be issued under a different
  series rather than under the 8859.

  TIS-620, indeed, specifies two code tables -- one is an eight-bit
  extension to the ISO 646 (US-ASCII) standard, the other one is an
  extension to the IBM EBCDIC standard.

  This registration request is specifically made for the ISO 646 extension
  table since this 8-bit charset has been used on the Internet during the
  past six years without proper registration. This request does not cover
  the EBCDIC version of TIS-620.

  While there are several vendor extensions to TIS-620, e.g. CP-874,
  MS-874/Windows-874, Mac Thai, etc., TIS-620 is still the most common
  denominator and is used for data interchange to maintain full
  compatibility among various platforms. Since these extensions are not
  fully compatible with TIS-620, they are not covered by this request.

RFC 2278 registration requirements conformance checklist:

3.1 Required characteristics
     x The proposed charset is a "Coded Character Set" per definition
       described in sect 2.4 of RFC 2278. 
     x The proposed charset is intended for use in MIME content type
       under the "text" top-level type and comforms to the restrictions
       of the "text" top-level type in RFC 2045.
     x The proposed charset is suitable for use in MIME.
3.2 New charsets
     x The proposed charset is NOT a new charset. It was first released by
       the national standards body in Thailand, the Thai Industrial
       Standards Institute (TISI), in 1986 and revised to the present form
       in 1990. There is no change in code-point assignment between these
       two versions.
3.3 Naming requirements
     x Proposed name for the charset is "TIS-620".
     x The name conforms to the ABNF definition in sect 3.3 of RFC 2278.
3.4 Functionality requirement
     x The proposed charset functions as an actual charset.
3.5 Usage and implementation requirements
     x The proposed charset has been fully adopted by the market and
       virtually every computer and software vendor doing business in
       Thailand. It is currently the only charset used for thai
       information interchange in the country.
3.6 Publication requirements
     x The proposed charset has been published by the Thai Industrial
       Standards Institute, Ministry of Industry, Royal Thai Government
       in 1990.
     x An online copy of Thai version of the standard can be viewed at
       <http://www.nectec.or.th/it-standards/std620/std620.htm>.
     x Code-point assignments for the proposed charset can be viewed at
       <http://www.inet.co.th/cyberclub/trin/thairef/tis-620.gif>
     x An cross reference table between TIS-620 and ISO/IEC 10646-1
       is available at
       <http://www.inet.co.th/cyberclub/trin/thairef/tis620-iso10646.html>
     x References to the Thai IT standards are published at
       <http://www.nectec.or.th/it-standards/> while implementation notes
       are available at <http://www.fedu.uec.ac.jp/ZzzThai/references.html>
       and <http://thaigate.rd.nacsis.ac.jp/refer/index.html>.
3.7 MIBenum requirements
     x A MIBenum value for the proposed charset will be assigned by IANA
       at the time of registration.

Charset Name(s):

TIS-620         This charset is to be used as a MIME text/* media type.

Published specification(s): 

[TIS_620-2533:1990] Thai Industrial Standards Institute, Ministry of
  Industry, Royal Thai Government (1990). UDC 681.3.04:003.62.
  ISBN 974-606-153-4.

  An online copy of Thai version of the standard can be viewed at
  <http://www.nectec.or.th/it-standards/std620/std620.htm>.

Person & email address to contact for further information:

  Trin Tantsetthi
  c/o Internet Thailand Co Ltd
  12th Floor, Bangkok Thai Tower Bldg
  108 Rangnam Street, Phyathai
  Bangkok, THAILAND 10400
  email: trin@mozart.inet.co.th


