The second hidden track indicates that it seems to be the artist’s intention that these tracks should be found by the listener in some way. Therefore, I think these tracks should be listed in the release.
The question now is how to do it right. Should these tracks be listed at all? Should these tracks be marked as hidden tracks by prepending/appending ‘[hidden]’?
Absolutely list them. Then put notes into the annotation as to their hidden status.
It is very likely these are “Easter Egg” type tracks. Something on the menus will light up and let you click it. I have a few DVDs like this with hidden bonuses.
There could very well be a way to access these from the menu system, but the method to do so may be extremely complex and non-discoverable. The menus work by executing software on the DVD which is pretty flexible aside from the limited amount of memory available to it, and some video games were made that are playable on standard DVD players.
For example, maybe after starting the main program you have to do something like press up, up, down, down, left, right, left, right, enter, menu.
I have a similar case with https://musicbrainz.org/release/d94b576c-d7a2-4ce5-94a7-8d33e2291cd7 that I’ve been meaning to ask about. The original music videos for the singles are included on the DVD, but they’re not on the tracklist and I can’t see any way of accessing them from the DVD menus.
The key is you found them, so they are on the DVD and can be listed.
Sometimes these Easter Eggs have to wait for a timer to go off before a hidden option appears. May be clicking a logo. All kinds of little tricks. But the main key is you have found content on the disk and can list it. This will help others who own the release to access the content you have found.
As to naming - you could put (hidden track) on the end of the track name if you want to make the point that they are hard to find.
