Currently all special purpose entities, e.g. Various Artists, [unknown] and [anonymous] are English named but for releases in other languages it’s odd IMO to see a [hidden] track inside a track listing in a different language.
Is it allowed to translate those entities? I couldn’t find anything in the docs or this forum.
Personally I enter Hebrew various artist releases as Various Artists credited as אמנים שונים: Artist credit “אמנים שונים” - MusicBrainz
Is that acceptable?
One more thought: artists are easy because they’re an actual linked entity and easy to search for but things like [untitled] tracks would be harder to find if they are written in different languages.
IMO it’s good.
I was using Various Artists, credited as オムニバス or サントラ or オルゴール for example (widespread Japanese VA).
These artist credits were all removed, long time ago, although I think it was a mistake to remove them, then.
Ah, I found the topic back, it was not so long time ago:
I agree with the localisation of special purpose entities, it makes sense for them to be displayable in the language of the release being used, even if the primary display in English to match the rest of the site.
The question is whether they should be localised by the editor or GUI.
The releases are localised by the editors, so, IMO, it should be the same for the special purpose artists that appear in them.
How do you make that consistent then?
What do you mean, consistent?
Consistent with what? 
To make a release consistent, I was using artist credit in the same language.
Once you click Various Artists, you see the artist in its main name, regardless.
Not using artist credit means the release is not consistent, it has a somehow unwanted English artist name, compared to how the release is usually listed elsewhere (like in shops).
In France, Various Artists is often credited as Compilations.
Never seen it as Various Artists.
In Japan, it is almost always credited as オムニバス (Omnibus) or as サントラ (soundtrack, OST), depending on type.
I’m not talking only about artist credits but things like [untitled] (Style / Unknown and untitled / Special purpose track title - MusicBrainz).
Artist credit does not block searchability, hopefully.
And I don’t think consistency of artist credit between releases is a good idea.
It’s not what artist credit was created for.
But, it’s not the end of the world.
I have often translated these sorts of artists as printed: “Tradicional” instead of [traditional] or “Anonyme” instead of [anonymous] seems fine to me. Sometimes I’ll use “French Traditional” or whatever as credit as well if that’s what’s printed, etc.
I don’t much like the idea of making up a translation that is not printed though. In that case I’d personally probably just default to the, well, default - except maybe in a pseudo-release
I’m just saying the default should be according to the release language.
I understand, I’m just not sure I agree 
That seems like something that should be done by taggers, not in MB proper?
Created https://tickets.metabrainz.org/browse/PICARD-3039 to do that in Picard.
In Picard, I think this sort of thing can be done using a tagger script something like (untested code):
$set(artist,$replace($%artist%,[unknown],[your translation of unknown]))
$set(artist,$replace($%artist%,[anonymous],[your translation of anonymous]))
$set(albumartist,$replace($%albumartist%,[unknown],[your translation of unknown]))
$set(albumartist,$replace($%albumartist%,[anonymous],[your translation of anonymous]))
$if($eq(%title%,[untitled]),$set(title,[your translation of untitled]))
As for “Various Artists” and “standalone recordings”, these can be set in the Metadata Options settings page in Picard.
Of course, this will only use whatever you have entered, and not be different for each different release language or selected user language.