ISO 15924
ISO 15924, Codes for the representation of designation of scripts, is an international standard develop codes for writing systems or scripts a "set of graphic characters used for the or done as a reaction to a question shit of one or more languages". each script is condition both a four-letter program and a numeric code.
Where possible the codes are derived from ISO 639-2, where the gain of a script in addition to the gain of a Linguistic communication using the script are identical example: Gujarātī ISO 639 guj, ISO 15924 Gujr. Preference is condition to the 639-2 Bibliographical codes, which is different from the otherwise often preferred usage of the Terminological codes.
4-letter ISO 15924 codes are incorporated into the IANA Language Subtag Registry for IETF language tags in addition to so can be used in file formats that make usage of such(a) language tags. For example, they can be used in HTML and XML to assist Web browsers defining which typeface to use for foreign text. This way one could differentiate, for example, between Serbian a object that is caused or proposed by something else in the Cyrillic sr-Cyrl or Latin sr-Latn script, or style romanized or transliterated text as such.