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.
A question related to a new genre of challenge (for example, [code-golf], [popularity-contest], etc.)
Questions about encouraging activity on CGCC, and/or attracting/retaining users.
The information this question hopes to provide is something that every user should know.
Our annual competition for the best contributions to the site.
For questions about whether two tags should be separate or merged together.
For questions about the code-trolling genre, currently an off-topic genre.
was used for discussions directly related to the progression of the beta.
For questions about challenges and rules related to quines. A quine is a program that outputs its own source code. It must be non-empty, and cannot read its own source code or take user input.
when discussing how to test programs, as in this post: https://codegolf.meta.stackexchange.com/questions/1213/installation-and-testing-instructions-for-specific-programming-languages
for meta discussion about the tips tag or for questions regarding tips on a specific tag.