The tag similarity was created last month. It has empty tag info. Just by the name, there are two common uses of the word similarity in mathematics, namely similarity of matrices and similarity of geometrical objects.
Using a word with several meanings as a name of a tag often leads to inconsistent usage of this tag.
Currently there are 7 questions having this tag. Most of them seem to be about matrices. But I found also questions about cosine similarity.
Do we need this tag? If yes, what should it contain and what should tag-wiki look like? Would it be better to have a separate tag for matrix similarity and similarity in geometry?
EDIT: Since no answers were posted for some time, I have posted some poll answers, which math.SE users could upvote based on their preferences. (I think that posting answer with arguments why the tags should be kept/removed is better than simply polling. But since some arguments have already been posted in comments and no answer has been posted, I thought that this might be a good way to provide an option for members of this site to show their opinion on the matter.)