Is there a list with tag definitions?

[Carnage]

So, maybe I'm simply too stupid to find it, but is there something like a thread on tagging guidelines?

 

[Plykiya]

@Carnage most of the tags are just copied off of MU. Nothing fancy like a guideline or something like that

 

[Carnage]

Then, can you or somebody else at least tell me what the 'Game' tag is meant for, exactly?

 

[Plykiya]

video game elements
levels, stats, class system, etc.
could involve playing games as well, like shogi or chess or whatever

 

[Carnage]

So both; 'game' in the sense of a series revolving around board/video games, and series with RPG elements as often seen in isekai adaptations, then?

 

[Teasday]

Yes

 

[Carnage]

Hmm, thank you.

 

[ryoken]

I don't know if this will helping or not
All Manga Tags +
Explanation

 

[Carnage]

Not at all, actually.
As this was about MD tags in particular.

 

[Noms]

This is the MU genres definition list (previously mentioned by Plykia): https://www.mangaupdates.com/genres.html

It wouldn't have been useful for your question about the game tag, but plyk already answered that.
A lot of the general genre info is based off of MU's, so it can be a useful reference.