[ttml2] Pull Request: Clarify collisions with 'none' keword in tts:backgroundImage (#1020).

skynavga has just submitted a new pull request for https://github.com/w3c/ttml2:

== Clarify collisions with 'none' keword in tts:backgroundImage (#1020). ==
Closes #1020.

See https://github.com/w3c/ttml2/pull/1177

Received on Friday, 4 October 2019 03:32:33 UTC