[ttml2] Pull Request: Add note clarifying definition of [content element] (#276).

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

== Add note clarifying definition of [content element] (#276). ==
Closes #276.

See https://github.com/w3c/ttml2/pull/586

Received on Sunday, 21 January 2018 00:06:51 UTC