BCP 47 Extension T - Transformed Content
M. Davis, A. Phillips, Y. Umaoka, C. Falk · 2012
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.