The libraries tag seems to be used with two different meanings: for Emacs Lisp libraries, or for DLLs needed to use certain Emacs features under Windows.
Would it be worth splitting the tag into two? What would be good names for the new tags?
It seems most reasonable to me that
libraries should refer only to Emacs Lisp libraries. However, we also have a
package tag, and it seems to me that these could be synonyms, although they could be used in slightly different ways (
libraries for "built-in" code,
package for third-party code).