Editing ISO 639 (section)

==History==
The early form of ISO's language coding system was manifested by ISO/R 639:1967 titled ''Symbols for Languages, Countries and Authorities'', which aimed chiefly to regulate vocabularies signifying languages, countries, and standardization agencies of ISO member bodies. Its "language symbols" consisted of one- or two-letter variable-length identifiers in capitalized Latin alphabets, e.g. <code>E</code> or <code>En</code> for English; <code>S</code>, <code>Sp</code>, or <code>Es</code> for Spanish; and <code>In</code> for Indonesian. It was also allowed to use (the pre-1993 version of) [[Universal Decimal Classification|UDC]] numeral auxiliaries to indicate languages.

{| class="wikitable sortable mw-collapsible mw-collapsed"
|+ class="nowrap" | List of language symbols in ISO/R 639:1967
|-
! Name (English) !! 1-letter !! 2-letter !! UDC !! (1988) !! (Current Set 1)
|-
| Afrikaans || — || <code>Af</code> || <code>=393.6</code> || <code>af</code> || <code>af</code>
|-
| Arabic || — || <code>Ar</code> || <code>=927</code> || <code>ar</code> || <code>ar</code>
|-
| Bulgarian || — || <code>Bg</code> || <code>=867</code> || <code>bg</code> || <code>bg</code>
|-
| Chinese || <code>C</code> || <code>Ch</code> || <code>=951</code> || <code>zh</code> || <code>zh</code>
|-
| Czech || — || <code>Cs</code> || <code>=850</code> || <code>cs</code> || <code>cs</code>
|-
| German || <code>D</code> || <code>De</code> || <code>=30</code> || <code>de</code> || <code>de</code>
|-
| Danish || — || <code>Da</code> || <code>=398</code> || <code>da</code> || <code>da</code>
|-
| English || <code>E</code> || <code>En</code> || <code>=20</code> || <code>en</code> || <code>en</code>
|-
| Esperanto || — || <code>Eo</code> || <code>=089.2</code> || <code>eo</code> || <code>eo</code>
|-
| Spanish || <code>S</code> || <code>Es</code> <code>Sp</code> || <code>=60</code> || <code>es</code> || <code>es</code>
|-
| French || <code>F</code> || <code>Fr</code> || <code>=40</code> || <code>fr</code> || <code>fr</code>
|-
| Finnish || — || <code>Fi</code> || <code>=945.41</code> || <code>fi</code> || <code>fi</code>
|-
| Greek || <code>G</code> || <code>Gr</code> || <code>=75</code> || <code>el</code> || <code>el</code>
|-
| Hebrew || — || <code>He</code> || <code>=924</code> || <code>iw</code> || <code>he</code>
|-
| Hindi || — || <code>Hi</code> || <code>=914.3</code> || <code>hi</code> || <code>hi</code>
|-
| Hungarian || — || <code>Hu</code> || <code>=945.11</code> || <code>hu</code> || <code>hu</code>
|-
| Italian || <code>I</code> || <code>It</code> || <code>=50</code> || <code>it</code> || <code>it</code>
|-
| Interlingua || — || <code>Ia</code> || <code>=089.7</code> || <code>ia</code> || <code>ia</code>
|-
| Interlingue || — || <code>Ie</code> || <code>=089.6</code> || <code>ie</code> || <code>ie</code>
|-
| Indonesian || — || <code>In</code> || <code>=992.21</code> || <code>in</code> || <code>id</code>
|-
| Japanese || <code>J</code> || <code>Ja</code> || <code>=956</code> || <code>ja</code> || <code>ja</code>
|-
| Korean || — || <code>Ko</code> || <code>=957</code> || <code>ko</code> || <code>ko</code>
|-
| Latin || <code>L</code> || <code>La</code> || <code>=71</code> || <code>la</code> || <code>la</code>
|-
| Dutch || — || <code>Nl</code> || <code>=393.1</code> || <code>nl</code> || <code>nl</code>
|-
| Norwegian || — || <code>No</code> || <code>=396</code> || <code>no</code> || <code>no</code>
|-
| Polish || — || <code>Pl</code> || <code>=84</code> || <code>pl</code> || <code>pl</code>
|-
| Portuguese || — || <code>Pt</code> || <code>=690</code> || <code>pt</code> || <code>pt</code>
|-
| Russian || <code>R</code> || <code>Ru</code> || <code>=82</code> || <code>ru</code> || <code>ru</code>
|-
| Romanian || — || <code>Ro</code> || <code>=590</code> || <code>ro</code> || <code>ro</code>
|-
| Sanskrit || — || <code>Sa</code> || <code>=912.3</code> || <code>sa</code> || <code>sa</code>
|-
| Serbo-Croat || — || <code>Sh</code> || <code>=861/862</code> || <code>sh</code> || —
|-
| Slovak || — || <code>Sk</code> || <code>=854</code> || <code>sk</code> || <code>sk</code>
|-
| Slovenian || — || <code>Sn</code> || <code>=863</code> || <code>sl</code> || <code>sl</code>
|-
| Swedish || — || <code>Sv</code> || <code>=397</code> || <code>sv</code> || <code>sv</code>
|-
| Turkish || — || <code>Tr</code> || <code>=943.5</code> || <code>tr</code> || <code>tr</code>
|-
| Ukrainian || — || <code>Uk</code> || <code>=83</code> || <code>uk</code> || <code>uk</code>
|-
| Urdu || — || <code>Ur</code> || <code>=914.31</code> || <code>ur</code> || <code>ur</code>
|}

After decoupling the country code into [[ISO 3166]] in 1974, the first edition of the standard ISO 639:1988 ''Code for the representation of names of languages'' was published with a framework of uniformly two-letter identifiers in lowercase Latin alphabets, mostly identical in format and vocabulary to that of the current ISO 639 Set 1.

Since then, the standard has been adopted as a fundamental technology of the rapidly expanding computer industry ([[RFC 1766]]), leading to development of more expressive three-letter framework, published as ISO 639-2:1998, largely based on [[MARC standards|MARC]] codes for languages. The original two-letter system was redefined as ISO 639-1 in 2001.

Seeking for more extensive support of languages for widening applications, separate supersets of the ISO 639-2 namespace that cover individual languages and groups were established as ISO 639-3 and ISO 639-5, respectively. There was also an attempt to code more precise language variants using four-letter identifiers as ISO 639-6, which was later withdrawn and to be reorganized under another framework, [[ISO 21636]].

Relatively constant updates in parts of ISO 639 had been handled by each own authority in charge until the publication of ISO 639:2023, which harmonized and reunified the body text of former standards and brought about organizational change with a joint maintenance agency supervising all sets and issuing newsletters. The maintenance agency is located in Ontario, Canada.<ref>{{cite web|url=https://www.iso.org/maintenance_agencies.html#74575|title=Maintenance agencies and registration authorities|website=ISO.org|access-date=15 January 2025}}</ref>