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.
Questions also answered by the user asking, easily marked by the shaded user card attached to the answer.
For questions about the "on hold" status, which occurs for the first five days that a question is closed.
For questions about user accounts that have been deleted, or the general process of account deletion.
Indicates that the site developers were not able to replicate the behavior reported.
Questions about the live Markdown preview of posts as they're being typed.
Proposals for new entries for the FAQ repository on this site should use this tag.
For requesting clarification on a specific flag. Flagging again with a custom flag may also be an option.
For questions concerning citation posts from MSE and citation of other resources when posting here.
For questions related to using various languages on math.SE.
Cross Posting refers to posting the same question over multiple Stack Exchange sites.
blocked from asking new questions, or posting new answers.
For questions both about the built-in editor for this site and also for question about preparing posts using different programs.
For questions about the Winter Bash (or holiday hats) to celebrate the end of the year.
the Stack Exchange Network staging zone, where users come together to build new Q&A sites. New site ideas are proposed, discussed, and the best go on to beta.
For questions that have as their purpose the celebration of a milestone, either for a specific user or the site.
For questions about the user named Community ♦ present on Math.SE (and other Stack Exchange sites.)
Users may only earn a certain amount of reputation each day, with the exception of reputation coming from accepted answers and bounties.
For issues regarding the help center of Mathematics Stack Exchange.
The black bar across the top of every Stack Exchange site
tag for questions related to some other site from SE network. MathOverflow has its own specific tag (mathoverflow). If you want to ask about a site proposal, use (area51) tag.
For questions about the public lists of changes made to posts by a site's users. They are available for questions and answers by clicking the "edited X min ago" link, and on tag wikis as "history" and…
For questions about the mobile versions of Stack Exchange sites. For questions about the mobile apps, use the [android-app] and the [ios-app] tags as needed.
Ceiling and floor of the number of characters you can enter into various slots
Questions about suspected user spam, the Spam Flag or combating spam as a community
Indicates that the feature request will not be implemented, or that a bug will not be fixed at present time.
For questions about the copyrights of the StackExchange sites themselves or about the posting of copyrighted material by users.
should be used when you are expecting a large number of diverse answers to a question.