[ttml2] Pull Request: Add informative text clarifying line height and line stacking semanti…

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

== Add informative text clarifying line height and line stacking semanti… ==
…cs (#806).

Closes #806.

See https://github.com/w3c/ttml2/pull/825

Received on Monday, 11 June 2018 09:01:59 UTC