IMSC 1.2 FPWD Horizontal Review

Dear Web Security,

[CC TTWG for reference/archive]

TTML Profiles for Internet Media Subtitles and Captions 1.2 (aka IMSC 1.2) FPWD [1] was published on 2019-11-28. Prior to publishing CR we are required by the Process and by our TTWG Charter to have elicited appropriate Horizontal Review.

The substantive change in IMSC 1.2 relative to the previous version, IMSC 1.1, is to reference partially the TTML2 #font feature and its associated features #resources and #source. This change permits IMSC documents to reference external font resources, which document processors can dereference, for example for presentation purposes. This is in principle a similar feature to the CSS @font-face rule.

Given that:

  *   IMSC 1.2 is a profile of the TTML2 Recommendation [2];
  *   the security and privacy considerations in IMSC 1.2 are delegated to TTML2, with exceptions for specific TTML2 features with a security impact that are not supported in IMSC 1.2;
  *   the delta relative to IMSC 1.1 is to include a feature already present in TTML2:

we believe that no further security review is warranted.

If you disagree and would like to request further time to review IMSC 1.2 please let us know as soon as possible.

Otherwise, if all else is well, we hope to publish IMSC 1.2 CR on or around 2020-03-19.

Kind regards,

Nigel Megitt, Chair, TTWG

References:

[1] IMSC 1.2 FPWD https://www.w3.org/TR/2019/WD-ttml-imsc1.2-20191128/

[2] TTML1 https://www.w3.org/TR/2018/REC-ttml2-20181108/