Today I wanted to vote to close a question as a duplicate of the canonical one "how do I send an e-mail message to a professor" that was written some time ago. I don't remember exactly the words in its title, nor who wrote it, so I have a hard time finding it with the search feature.
Would it be a good idea to have a tag canonical-question (or maybe also "faq", "common-question") that is used to tag questions such as this one or the other frequently-duplicated one about journal workflow?
In this way I could simply search for questions with this tag. This tag would also help for new users, since by browsing the tag one finds quickly some of the best, most-useful, and most-asked questions and answers that this site provides.
If needed, the tag could be protected so that only moderators and/or high rep users can add it (is that an existing feature that can be enabled on a tag?)