> Want a youtube channel in your RSS feed? Just copy the channel's URL and subscribe to it in your reader.

You can also subscribe to playlists, by subscribing to

  https://www.youtube.com/feeds/videos.xml?playlist_id=PLAYLIST_ID

Where `PLAYLIST_ID` is the string after `?list=` in a YouTube URL. Unfortunately, that feed always contains the top 15 items in a playlist and many channels order items in reverse order (i.e. they keep the oldest one at the top and add to the bottom), unitising the feed.