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.
The question you're asking is designed to solicit opinions, influence site policy, or debate a particular topic, with the goal of reaching a community consensus.
A request for assistance from community, moderators, or staff with one of the site's features
Bug reports marked resolved or feature requests filed as done and live.
Something amiss or broken with how you're working with the site? Report it.
You have an idea for a new feature, or for a change to the existing functionality.
General questions about tag usage on the main site
Questions that are asking to have some questions retagged, usually for a misused tag, or generally removing a tag
Questions that deal with our cleaning up unwanted junk tags.
Use this to tag anything about asking questions in general
Anything about questions that were closed by community or a moderator
If you have any issues with a specific question, use this tag. Include the link to the original question, if possible.
Questions regarding reputation, see also [voting] and [privileges]
Anything related to posting answers, e.g. about improving their content, voting on answers, editing others' answers, etc.
Anything related to the editing feature, e.g. anonymous edits, suggested edits, the editing privilege, edit history, etc.
Requests to have closed questions reopened by community or a moderator. Please include arguments – why should the question be reopened?
To ask about flags, how to flag, when to flag, how flags work, and explanation why flags are declined.
A request to add one tag as the synonym of another tag. Please be specific about which tag should be a synonym of which. Bidirectional synonyms and cycles are implicitly disallowed, so suggest wisely.
Indicates that the reported behavior is intentional and not subject to change
For questions about the /review path where users can view and act on posts by other users that the system thinks may need attention.
Comments that can be added to questions or answers
Questions about the migration of posts to another Stack Exchange site
Questions about finding duplicates, handling duplicate content, voting to close, et cetera
Relating to the Super User Blog, including questions, topics, reviews, and requested features.
Questions about reasons for closing a specific question (use [specific-question] too), and the predefined reasons users are able to choose from when voting to close
Questions about current moderation policy and support about the way moderation works
For questions whether specific topics are in scope in superuser.
for questions specific to down-votes, the community's way of telling peers that their content can be improved. Down-votes on meta site have different meanings.
Any concerns about the scope of the site, as explained in the FAQ