5:43 AM
1

There is a tag complex-multiplication. Naturally, it's used for all sorts of questions about multiplying things. They don't even have to be complex numbers; as long as it's something complicated=complex, the name seems to fit perfectly. Yet, the tag excerpt says The theory of elliptic cu...

Was there some discussion of the tag before?
I vaguely recall that it was discussed somewhere. (I might be wrong.) I only found this:
Matt, I tried, but below 20K I can only suggest the description wiki. I know because I used a new one "complex-multiplication" recently and Willie Wong asked me to provide a description. It turned out that was not permanent, and he fiddled it into final shape the next day. — Will Jagy Dec 27 '12 at 21:02

None that I remember; in fact I never noticed the tag until today, despite its age.

@WillieWong, created a tag and a vanilla tag wiki. I'm not sure people know what that is, i didn't when you talked about it for "complex-multiplication" — Will Jagy Aug 2 '13 at 20:30
Tag-excerpt was created by Will Jagy: math.stackexchange.com/posts/256569/revisions Tag-wiki was created by Willie Wong: math.stackexchange.com/posts/256568/revisions
Oct 11 '15 at 20:48, by Martin Sleziak
Martin, saw your comments at my "new/rare tags" answer, thanks. I simply deleted it. The first time I made a tag, complex-multiplication as in the David Cox book Primes of the form $x^2 + n y^2:$ Fermat, Class Field Theory, and Complex Multiplication, Willie Wong asked me what should go in the tag information; later he said he was mostly worried people would use it for instructions about how to multiply complex numbers. Anyway, i did figure out that I was supposed to put in some information for any tag I made; there have not been many. — Will Jagy 1 hour ago
So there are several references in the comments (the last one is now deleted) to the fact that Will Jagy created the tag and Willie Wong asked him to created tag-wiki. (However, I did not find meta-post, comment, chat conversation where this happened.)
Ok, probably this is where it happened:
@WillieWong, I'm under 20K so I guess I proposed such a line. I just carried over the tag from MO, and do not really know how it should be described. I do have reason (an expert) to believe it plays a part in my question. — Will Jagy Dec 11 '12 at 21:03
@WillJagy: okay. With the hints you gave I found the Wikipedia article and put in a stub. Mainly I want to clarify that the tag should not be used for the multiplication of complex numbers. — Willie Wong Dec 12 '12 at 9:00
@WillieWong, I see you put that in, about not multiplying complex numbers. All I know on the topic is in the David A. Cox book Primes of the Form $x^2 + n y^2.$ However, it was actually a comment of one Jonathan Hanke that the example in this question is CM, out of roughly 25 very similar examples. — Will Jagy Dec 12 '12 at 22:10
@LiveForever I have pinged Will Jagy. I think that it is good that tag-creator knows about discussion of the tag they created.
@WillJagy The tag (complex-multiplication) is now discussed on meta. — Martin Sleziak 39 secs ago

6:46 AM
I vaguely remembered that I have heard about the tag before. I thought there was a bit longer discussion, but it seems I was wrong. Probably I remembered it from Will Jagy's comment (now deleted) on my post. The comment was a reaction to my comments here.

13 hours later…
7:57 PM
I know that the notion of is useful, but it is important enough to have a separate tag?
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While reading a paper, I came across these definitions and claims: Definition: Given $p \in \mathbb R^d$, and $H$, a set of hyperplanes, let $\text{Violate}_p(H) = \{h \in H: h \text{ is strictly below } p\}$. Definition: A subset of $R \subseteq H$ is an $\epsilon$-net of $H$, if for ev...

0

When searching for "trigonometry" or something similar in the tag list (or when editing a question), the trigonometric-functions appears, and is said to contain 72 questions: But there's a twist: trigonometric-functions is a synonym of trigonometry, which has 10k+ questions, and the following ...

8:29 PM
Based on the comments to the above question, this seems to be one of the differences between merging and synonymizing two tags.
5

Two tags can be made synonyms and they can also be merged. What is the difference between these two things? I am referring here to the terminology used in this post. It contains a list of changes in tags, some of them are marked by m for "merge", some of them are marked by s for "synonym". ...