BCP 47 Extension T - Transformed Content
Google
Infinite Automata
Lab126
IBM
This document specifies an Extension to BCP 47 that provides subtags for specifying the source language or script of transformed content, including content that has been transliterated, transcribed, or translated, or in some other way influenced by the source. It also provides for additional information used for identification. This document is not an Internet Standards Track specification; it is published for informational purposes.