@ArnaudD. There are, IMO, some difference between e.g. real-analysis, abstract-algebra, and e.g. differential-geometry, algebraic geometry. For example, for real-analysis, it covers of course all introductory analysis, some might also uses it for question in measure theory. But if you go a little bit ahead, it seems unnecessary to use this tag for questions in PDE, harmonic analysis.... at some points there seems to be a cutoff for the real-analysis tag.

Some for DG, I don't think there is.

No wiki and usage guidance for euler-method, though created years ago.

Just want to hear more people's opinion: Who is in favour of keeping the tag gre-exam? Related: Tag request: csir-net-exam

There is a similar tag gmat-exam. And there was a suggestion for other tags related to a specific type of exam: chat.stackexchange.com/transcript/3740/2017/12/16

Possibly it might be reasonable to make a post on meta to discuss all these various types of exams - whether there should be tags for them.

I'm actually coming from Henning's answer and consider reposting it on Tag management 2019

That sounds reasonable. Still, maybe it some point tags for exams (contest exams) might be discussed in general.

The tag old-question-papers had at least the advantage that it was not tied to a specific exam, but the choice of the tag name was rather unsuitable.

So is question-exam-recommendation. From Why don't we create the tag question-exam-recommendation?, it seems the general opinions are against the creation of such type of tags.

From what I read there, this tag tag was in a different spirit. It was not tied to GRE, GMAT, CSIR, TIFR, etc. It was intended as "questions suitable for an exam". Which is rather vague and definitely opinion-based - so I am not surprised by bad reception of that particular suggestion.

Would a qual question tag be useful? looks like a general discussion of qualifying exam tags.

Good find! I did not remember that question.

Should we remove the tag eulers-number (4 questions with the tag currently)? I think exponential-function already encompasses eulers-number (notice a synonym of exponential-function is e)

I have mentioned the same tag when it was created: chat.stackexchange.com/transcript/3740/2019/1/29

Definitely, eulers-number and e should be synonyms.

The question is whether e should be a synonym of exponential-function. (Although at this point, cancelling the synonym would mean quite a lot of work in retagging older questions.)

Maybe we can edit the tag wiki and tag excerpt to make explicit questions about Euler's number per se can be tagged with exponential-function? (it's unclear at present that it is actually a synonym of e)

Tag excerpt and tag wiki of euler-method. Feel free to add more.

Thanks for editing the tag-info, it is really appreciated!