• The Timed Text Working Group has published IMSC Text Profile 1.3 as a W3C Candidate Recommendation Snapshot. • IMSC 1.3 defines a text-only profile of [ ttml2 ] intended for subtitle and caption delivery applications worldwide. • It improves on IMSC 1.2 Text Profile by adding support for superscript and subscript text, and provides authoring guidelines for the Japanese language. • The IMSC 1.2 Image Profile is not reproduced within IMSC 1.3, and the IMSC Hypothetical Render Model [ imsc-hrm ] is now a separate Recommendation, referenced by IMSC 1.3. • Comments are welcome via Github issues or email to public-tt@w3.org by 15 January 2026 .
Article Summaries:
- The W3C Timed Text Working Group has released the IMSC Text Profile 1.3 as a Candidate Recommendation Snapshot. The new profile extends the text‑only subset of TTML 2.0, adding support for superscript and subscript characters and providing authoring guidelines for Japanese subtitles and captions. It does not include the IMSC 1.2 Image Profile, and the IMSC Hypothetical Render Model has been moved to a separate Recommendation that is referenced by IMSC 1.3. The W3C invites implementations and welcomes comments via GitHub issues or email to public‑tt@w3.org by 15 January 2026.
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