A decade ago, this question was asked about the names of the inverse trigonometric functions. At the time, it received a Nice Answer, which was accepted, as well as a few other answers and comments. Two days ago, a new user posted another answer which did not address the original question, and which was deleted by 3 trusted users. This is all perfectly normal.
But then the original question was locked, and I cannot understand why.
A locked post does not accept answers, comments, or revisions. It is frozen in time, and can only be unlocked by a moderator. The explanation given on the question is that it is off-topic, but is kept because of historical significance. Which begs the question: Why is it off-topic to inquire about the names of the inverse trigonometric functions? It is a direct question that has a straight-forward answer, and knowing the answer will improve your understanding of trigonometry.
The impression of a locked post is that questions of this nature are not welcome on this site. This is in contrast to a closed post, which may be on-topic but in need of improvement. Searching for etymology on Main gives more than 100 questions about terms and their meaning. Which of these questions are off-topic?