Non-existent releases may be on the MB. For example, BUMP OF CHICKEN’s “Mayday” has a release on MB called “With additional silence track” that splits the third track in two.
These two releases have exactly the same catalog numbers and barcodes.
I don’t think I need it, what should I do?
Why do you think that release doesn’t exist? By default I’d trust the editor that added it.
it’s been entered as a Pseudo-release, which is used for such cases - it is fine, please do not remove it.
Both of those releases have DiscIDs. So will exist in some form somewhere like that. The Pseudio-release is a translation to English. All three seem legit.
However only one of them is present in CUETools DB so I’d take it (the “pseudo-release”) with a grain of salt.
I directly asked the original editors, it’s what you should do, IMO. 
The pseudo-release does not have a discID. That is only there to show the titles in English. The question is between the two official releases.
I assume the original is three tracks for the hidden track to function as planned.
If the other is a homebrew then they have kept to same exact track lengths.
-=-=
To extend the puzzle, have a look at [ silence ] by BUMP OF CHICKEN Recording “[silence]” by BUMP OF CHICKEN - MusicBrainz I think they do this a lot with their music. My guess you’ll find other CDs like this too
Following that thought I found this release edit history interesting: https://musicbrainz.org/release/63416d6a-d144-428f-8663-1db6f855b545/edits
Scroll to the first edit note. “Decided to add this release since this is how the rip I have is structured but don’t have the original CD to make sure. Anyway this should make it easier for others in tagging.” That is the same @Benji99 who then adds the discIDs with the silence as a separate track.
So “follow the [ silence ]” to locate the other “CDs” where this happens. My money is each time you see a CD with the silences separated it was added by @Benji99
One thing I will point out is this is actually useful data. By doing this they have given the exact music length of each hidden track. Basically have shown how the silences are laid out on these recordings. Maybe worth preserving as a pseudo-release but with an annotation note. OR at least put these length details into the recordings.
Interesting observation on the use of [silence] tracks on other releases by the band.
I’ve looked around a bit, and what struck me is that Amazon has an entry of the single labeled “Japan version”. That corresponds to the ASIN linked to the three-track release.
The online store YesAsia.com lists tons of BoC releases as “Japan versions” as well and in at least one case also has an entry for an “overseas version” for the single “Planetarium”. They only list the A-side and B-side tracks for both versions, so it’s impossible to see mastering differences for how the silent and hidden bonus tracks are cut, but the Japan and overseas versions of “Planetarium” might explain the two releases in the release group with [silence] distributed over different track counts:
Can’t find an overseas version of “Mayday” via Google, though, but the explicit naming of a “Japan version” by two stores looks like a good indicator some other version may have been sold, possibly with the mastering differences as we see in the release group.
At least nine different albums added by @Benji99 like this. All with a matching discID.
Lets look at a different release:
This time we have a nine track edition with six silent tracks 5 seconds long, followed by another hidden track with 9mins of silence at the start of it (according to Discogs)
@Benji99 version has the silence adjusted into one lump.
Maybe these are represses of some form?
I assume if these came out on streaming the gaps would be removed.
Unfortunately, the streaming service does not include hidden tracks.
I have not received any replies. After all, what am I to do about this non-existent release?
I got an answer that the 3 track edition does exist.
Now, the 4 track edition…
But I haven’t got answers to my edit note so I think that these releases with addition of the silence track by this editor could be removed, and the ones found by @IvanDobsky , as well, if “the real one” does exist besides:
Same as other release […] with added silence track
According to edit notes, none of the releases are based off a real release in hands, but from some rips found somewhere.
Which would mean that fake Disc ID would have been built and submitted?
I also find it in GnuDb, but with a quite MB specific way of noting the [silence] track…
Why submitting TOC/Disc ID for a release that does not exist? 
The way I was reading the edits seemed to be these were ripped, and then the discs sold. Or ripped from a friend. Every release added in this way has a discID. It does not really make sense to make up faked discIDs - what would be the point?
Note also that the first tracks are all exact length matches so we aren’t talking sloppy CD-R home brews. As these hidden tracks were not on the streaming service this isn’t someone rebuilding a CD from digital media.
Leaving questions on edit notes is always a bit hit or miss. A lack of reply does not mean a lack of fact.
Discogs is no help here as the few times they do have this release they have just done their “as written on cover” method and rarely mention the size of the silence.
I don’t see what is wrong with leaving these in place, but with annotations. Especially as they are currently the most accurate way to know the length of the bonus tracks.
Creation and registration of discIDs can be easily accomplished by creating “virtual CD” through slight text editing of a .cue file ripped from the original CD, without burning a CD-R.
It would be appropriate to treat this 4-track discID/release as a “homemade bootleg” created in this way.
There are no 4-track “メーデー” in the free CDDB services used by numerous users in Japan. And, I checked some BUMP OF CHICKEN registrations and could not find any such ‘hacked’ data. Therefore, I believe it is not official.
If they are to be deleted, could I suggest someone edits a note to the “hidden tracks” to add their actual audio lengths.
Quickest way to find all the releases is “follow the silence” as I showed above.
I’ve added my own share of rare CDs that don’t exist on other databases. Which is why I was giving this editor the benefit of doubt.
I will remove these “non-existent releases” based on this thread. I will add appropriate information to the “releases that exist” as needed. Please vote Yes.
https://musicbrainz.org/user/yakumo0209/edits/open
Before they disappear and losing info, you should quickly edit the original recordings, at least (and the original tracks maybe).
It should be done before deleting, actually.
And if the split recordings have AcoustID, it could be nice to link those split recordings to the big original recording, as compiled, to keep data.
Credited Work / Uncredited Work
- Credited Work MM:SS
- Silence MM:SS
- Uncredited Work MM:SS
I will not vote as I don’t agree. But please write annotations on the recordings to note their real length. The original editor had done the work to make it clear how long they are.
And don’t delete the recordings, they should be merged. Same with the releases, they should be merged. Just a normal guideline around here to preserve MBIDs