Ok, if you think that the tag-info from some of the other sites could be copied (or combined or modified) to a useful tag-info on MathOverflow Meta, feel free to edit it. There is also a tag editor badge for that.

Concerning the language, it is interesting that similar thing to French is also in Slovak and Czech.

You have mentioned the two meanings: 1. tag, label, 2. etiquette. This is true for French étiquette, and also for Slovak/Czech etiketa.

I have never seen it used in that way, but according to Wiktionary also in English the word etiquette can have somewhat similar meaning. One of the meanings in Wiktionary is given as: "A label used to indicate that a letter is to be sent by airmail."

I did not know that there are two meanings in French (but I do not speak French, so that's not surprising). And I did not know about the alternative meaning in English, either.

new-tag A new tag infinity was created. It seems that this tag was created before in 2017 in a post which is now deleted. This post was closed and downvoted, so it might get deleted eventually.

I guess that (infinity) might be a bit too vague to e useful as a tag.

SEDE: data.stackexchange.com/mathoverflow/query/927958/… data.stackexchange.com/mathoverflow/query/883845/…

@MartinSleziak actually the previous and current occurrence of the tag is by the same OP. Is there any useful reason to edit the previous deleted question to remove the tag?