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.

used for questions that ask users to discuss an idea, concept, or problem in an abstract way. A discussion question may not necessarily have a clear-cut right or wrong answer and is often…
5395 questions
A request for assistance with one of the site's features.
used to write mathematics on Stack Exchange sites.
941 questions
You have an idea for a new feature on the site, or for a change to the existing functionality.
925 questions
Indicates a reproducible problem on the site that you believe is due to a mistake, malfunction, or programming error.
keywords or labels that categorize and group your question with other, similar questions. If your post at meta is about suggesting new tags, choosing correct tags for some question, suggestin…
600 questions
when asking what is on- or off-topic on the main site, and why.
when you want to draw attention to a specific question on the main site. For example, if you want to draw high-rep users to close/reopen/edit a question, if you want to discuss the…
small addendums to each question or answer, intentionally limited in size and formatting.
a core, fundamental Stack Exchange value -- we allow editing by registered and unregistered users (if peer reviewed).
will be used to ask questions dealing with reputation.
For questions about the /review path where users can view and act on posts by other users that the system thinks may need attention.
For questions about answers on the main site. Consider using the accepted-answer tag if the question is about an answer that has been accepted.
272 questions
Indicates that the report has been resolved through the implementation of a feature or the fixing of a bug.
264 questions
Questions specifically about the process of asking questions on this site.
The process by which users can vote a question closed if it is off-topic or otherwise disallowed by the FAQ.
the process of bringing a question, answer or comment to a community moderator's attention for any reason.
the community's way of telling peers that their content can be improved. Downvotes on meta may have different meanings.
233 questions
for questions about questions, answers and comments that have been deleted, or nominated for deletion.
referring to the process of identifying and closing questions that are exact duplicates of another question.
218 questions
aimed for discussions about etiquette: how to behave on the site and the chat.
Users without full edit privileges can suggest edits to posts and tag wikis
a way to get additional attention for a question by offering some of your own reputation for great answers.
178 questions
For instructions and guidance on closing or migrating questions, and the reasons for those closures.
172 questions
refers to all questions deleted from Stack Exchange sites. The tag 'specific-question' should also be used when referencing a specific question that has been deleted.
the primary way users gain reputation, and also how many items are sorted to the top.
162 questions
For questions about built-in search functionality of this site and about searching this site using external search engines.
The user interface elements and web pages that make up this site.
awarded to encourage and incentivize positive community actions within the site.
For questions concerning the management of tags on both the main site and meta. Common topics include the merging of tags, and making tags synonyms of one another.
Questions about diamond (♦) moderators, their powers, and actions they have taken.
the answer the question owner thought best met their needs. Accepting is encouraged but never required. This tag is for *discussing* issues related to accepted answers, not indi…
125 questions
For questions on Mathematics Stack Exchange policies.
For questions concerning using images in questions, image hosting etc.
For talking about questions which have been closed.
Refers to user accounts either generically, or across the network.
109 questions
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