The tag elementary-number-theory was created and removed a few times in the past. And recently it was created again - it is still listed among the new tags.

- Should there be a separate tag for elementary-number-theory on MathOverflow?
- If yes, what should be the content of this tag.

You can see links to the previous occurrences in the MO editors' lounge. Specifically:

- This tag was created and removed in 2012: https://mathoverflow.net/posts/83904/revisions.
- Then again in November 2013: https://mathoverflow.net/posts/31113/revisions https://mathoverflow.net/posts/146589/revisions At the time, this tag was discussed by several users in the MO editor's lounge. (Interestingly, the discussion in chat mentions five questions - using SEDE queries I was only able to find two.)
- Another occurrence was in December 2013: https://mathoverflow.net/posts/144996/revisions
- And the tags was created again now in 2023. After approximately on week, there are three questions with this tag.

I decided to ask because on Mathematics Stack Exchange there are some problems around this tag - it is unclear whether elementary-number-theory should be a subset of number-theory or whether the latter should only be for more advanced questions.^{1}
On MathOverflow it is unlikely that there would be a similar problem - since among the top-level tags^{2} there is nt.number-theory, which should include elementary-number-theory, too.
Still, since this tag was created and removed more than once, it seemed reasonable to bring it up on meta.

^{1}Discussion on Mathematics Meta: There are 5,931 questions tagged both elementary-number-theory and number-theory and How to differentiate between (elementary-number-theory) and (number-theory).

^{2}Why are MO tags formatted as they are? and Frequently asked questions about tagging on MathOverflow