https://lists.w3.org/Archives/Public/public-html/2014Apr/0060.html
Re: addTextTrack test bug (Re: HTML5 CR "at risk" features) from Boris Zbarsky on 2014-04-15...
https://www.w3schools.com/TAGS/av_met_addtexttrack.asp
HTML Audio/Video DOM addTextTrack() Method
Well organized and easy to understand Web building tutorials with lots of examples of how to use HTML, CSS, JavaScript, SQL, Python, PHP, Bootstrap, Java, XML...
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