[webvtt] Tweak text around conformance classes

zcorpan has just created a new issue for 
https://github.com/w3c/webvtt:

== Tweak text around conformance classes ==
See https://github.com/w3c/webvtt/pull/261#discussion_r44954702

Please view or discuss this issue at 
https://github.com/w3c/webvtt/issues/268 using your GitHub account

Received on Wednesday, 18 November 2015 08:04:35 UTC