Apparently I inadvertently irked a moderator by creating a tag. The moderator told me that my tag was "meta" and therefore not appropriate. Having been a SO user for a long time (and a lurker on MetaSO), it was not clear to me what makes my tag "meta" and why meta tags would be inappropriate.
Many of the questions I see on SO aren't really about the topics in the title or the existing tag list. For example, "C++ SetWindowText not working", isn't really about C++ or SetWindowText (or the Windows API as tagged). It's simply somebody who had a bug, couldn't find it, and tried to outsource the debugging. This seems to be a common category of question on SO. So I started tagged questions like this with the label "findmybug".
Lots of frequent SO contributors regularly answer questions in this category rather than voting to close them as "Too Localized". I took that as a cue that I should also try to answer rather than voting to close. But leaving these questions open and tagged with "c++" and "winapi" even though the question isn't really about C++ or the Windows API seemed misleading. Someone searching for answers on using SetWindowText from C++ probably isn't making exactly the same mistake and won't find that entry useful. (In the end, the sample question was closed as "Too Localized", but this doesn't seem common for these types of questions.)
The Tags page says:
A tag is a keyword or label that categorizes your question with other, similar questions. Using the right tags makes it easier for others to find and answer your question.
It seems to me that the "findmybug" tag does group these similar questions together. So from that perspective, it seems to fit. Lots of users seem to enjoy answering these types of questions, so it makes sense they'd want a way to find them.
If you want to suggest that all the questions I would tag as "findmybug" should be closed as "Too Localized", that's fine. But I'm trying to ask the more general question: What makes a tag meta, and are meta tags inappropriate?