The tags and appear to be synonyms. The tag has a (short) wiki entry while does not, and there are roughly six times as many questions tagged , so even though I'd personally prefer to be the base tag, it appears the community would prefer to use .

  • There's also the find-and-replace tag which should be added into this somewhere.
    – animuson StaffMod
    Commented Nov 30, 2012 at 18:43