Is it appropriate to add a tag that applies to the accepted answer rather than the question?

Question

In the question posted here the OP uses suitable tags for the question, namely tikz-pgf, tikz-arrows, graphs.

The accepted answer (mine) uses tikz-cd. Is it appropriate to add the tikz-cd tag to the question? The use of tikz-cd in the answer is somewhat atypical (for beginners), using nodes for cells, so I thought the tag might be helpful from a search perspective.

Answer 1

The general position has always been that tags are about questions, not answers. So tagging because an answer (accepted or not) uses a particular package has not been regarded as desirable.

Answer 2

Occasionally there are answerers that put a tag at the start of an answer, as a visual way of saying "This answer uses such-and-such package or technique". Stack Exchange has markdown for that.

For example, [tag:tikz-cd] looks like tikz-cd. This button is also a link to all the questions with this tag, i.e., https://tex.stackexchange.com/questions/tagged/tikz-cd. On the main page this also shows the tag excerpt on mouseover. For Meta the equivalent (with a link and mouseover) is [meta-tag:tagname], for example tagging.

I couldn't find any guidance on TeX.Meta or on Meta.SE if this is a good idea, but personally I find it helpful to add such a tag in case you use an approach that the asker did not know about, or an approach using a different package than mentioned in the question (which is perfectly valid by itself).

Your answer would look for example like this:

Or this:

The other answer could then similarly be tagged pstricks.