[ttml2] Clarify meaning of significant text node. (#1105)

skynavga has just created a new issue for https://github.com/w3c/ttml2:

== Clarify meaning of significant text node. ==


Please view or discuss this issue at https://github.com/w3c/ttml2/issues/1105 using your GitHub account

Received on Thursday, 30 May 2019 17:03:00 UTC