[ttml1] Pull Request: Specify timing semantics for <br>

palemieux has just submitted a new pull request for https://github.com/w3c/ttml1:

== Specify timing semantics for <br> ==
Closes #339

See https://github.com/w3c/ttml1/pull/340

Received on Tuesday, 6 February 2018 07:09:46 UTC