In an application I generate Web VTT video subtitle files using input from users and other data sources.
Generally this works fine, but I can't figure out how to show a subtitle line in Firefox starting with the string "NOTE". Example:
00:00.000 --> 00:02.000
NOTE A
This should show the subtitle "NOTE A" for the first two seconds. In Chromium 89.0 this works fine, but Firefox 87.0 doesn't show anything.
I also can't find a hint for escaping "NOTE" here: https://developer.mozilla.org/en-US/docs/Web/API/WebVTT_API