My meta post hasn't received much attention (several comments, but only 1 upvote and 0 downvotes), but I think comparison with, e.g., curl makes the case pretty compelling for its addition. math.meta.stackexchange.com/a/30915/155629 Is it permissible to add the tag in this situation?

If so, what is the etiquette for populating some existing questions with the tag? In the past when I've added a new tag I've just searched and added the tag to a dozen questions or so, but I understand there's good reason not to bump too many questions to the front page at once.

It's just a few messages up, but to be clear my previous two messages concerned my proposal to add a gradient tag.

@WillieWong Since you're the user who removed the previous instance on this tag, maybe you'll have something to say on the question whether or not gradient would be a useful tag.

Is it a good idea that when posting a request in the Tag management in meta, user should also link to several (say 3) posts in main, where the proposed tags would be used? On one hand it justifies the proposal (if that is not even 1 question in main that the tag could be used, then the tag is probably useless), but more importantly it facilitate the discussion.

@TravisWillse Perhaps if you wait a litte bit, you'll get some additional feedback from other users.

I have recently bumped your post by editing the links into it. (BTW would it maybe be reasonable to count only questions for this purpose?)

I think that Arctic Char's suggestion is very reasonable.

Are there some older posts where you think it would be important to add the tag.

Clearly, nobody is going to retag approximately 5k questions. But are there some of them which somebody should definitely find when searching using this tag? Are there some past posts about the topic which are rather important? Are there some types of questions which appear repeatedly?

I thought about the same thing - partially because of some tag-related discussion on MathOverflow Meta not too long ago.

Another thing which possibly might be included in the post suggesting a new tag is a proposal for the tag-info. (Although in this case it is relatively clear from the tag name what it is supposed to be used for.)

@ArcticChar @MartinSleziak Thanks for all the helpful feedback. I've updated the question to incorporate all of your suggestions, which I think has substantially improved my post. I'll wait a few more days to see whether it draws any more feedback.

@TravisWillse Thanks for the edits. Since you changed the wording to 6.5k results for gradient, I suppose that you wanted to link there to math.stackexchange.com/search?q=gradient+is:q (the search for questions)rather than math.stackexchange.com/search?q=gradient.

Although I see that in the two bullet points about curl and divergence you also have link to all posts while the counts are from results with is:q.

As I am not exactly sure what you actually prefer, I commented here (rather than editing the post myself). Nevertheless, I think that including some kind of link is useful - the users reading your post can check whether the numbers are correct and can also do some searches with additional keywords if they want to analyze the search results a bit more.

You're right, I intended to update the links, and have now done so. Thanks for the correction!