Custom channel M3U Playlist tags documentation?

A couple questions on the M3U Playlist tags Documentation

It states channel-id is a REQUIRED unique ID tag per channel, but it appears if that's missing it falls back to using the tag tvg-name (channel callsign) for the ID?

The following tags are not mentioned (are they used by Channels DVR?)

  • group-title (appears to be used by Channels DVR)
  • tvg-id (appears to be REQUIRED to match up with xmltv epg <channel id> and <programme channel>)
  • tvg-chno