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.

intentional and not subject to change
103 questions
Questions about sizes and other quantities of MSE, e.g. number of questions, GB/day transferred, etc.
For questions about real time web chat that accompanies Mathematics Stack Exchange site.
Here, "design" refers to front-end elements, such as page layout, coloring conventions, etc. For questions about database structure, algorithms in the code, &c., please use the tag [architecture] inst…
90 questions
The process of migrating off-topic questions from one Stack Exchange site to another.
90 questions
held to choose moderators for the Mathematics Stack Exchange site.
Relating to the discussion and controversy around questions that are tagged, explicitly stated as, presumed, or suspected to be homework questions (i.e. those given to a student in a formal course of …
the process, to emphasize, layout and decorate a text for a better user-experience.
85 questions
a lightweight markup language used across the entire Stack Exchange network for post formatting.
84 questions
For questions which focus on a particular user, rather than those discussing general user issues. NOTE: For questions regarding suspected fraudulent behavior by specific users, please prefer flagging …
81 questions
allowable or desirable in question titles.
78 questions
The various user interface and email elements used to notify users of events on the site.
78 questions
designed to help new reviewers hone their moderation skills, while nudging more experienced users that don't seem to be paying close attention to what they're revi…
73 questions
no Meta Meta Math.SE, so questions about this very site just get this tag.
those questions which have neither an accepted answer nor answers with positive vote count. Note that our definition is strict!
70 questions
an editable page that briefly summarizes the topic of the tag and that may provide links to existing questions that are often useful to many people. Sometimes tag-wiki also includes short …
70 questions
For the discussion related to the MathOverflow site, our sister site for professional mathematicians.
Questions that deal with general issues regarding new users and their assimilation into the Math Stack Exchange community.
For questions on usage of links at MSE (both links to various parts of this site and to other sites).
66 questions
use for any questions related to deleted answers specifically.
66 questions
for questions specific to upvotes, the community's way of telling peers that their content was clear and helpful. Up-votes on the meta sites may have different meanings.
Questions about various privileges you obtain by earning reputation points.
63 questions
A tag for questions about the community wiki feature (regardless of whether or not the questions themselves are community wiki).
Questions dealing with moderator actions, pages, abilities or decisions.
for questions on Meta that relate to a specific answer on MSE. Do not use if your intention is to discuss/ask about a general issue, and you merely use some posts as examples.
60 questions
For questions about comment @replies (a.k.a. pings).
For questions relating to posts of low quality, generally or possibly with regards to specific users.
54 questions
the act of casting many successive upvotes or downvotes on the posts of a specific user.
For discussions about contest questions posted on this site.
For discussions related to re-opening questions.
The user profile page, which contains a list of all the questions, answers, and an audit trail of the user's activity on the site.
51 questions
For discussions about posts which ask for verification of OP's solution or proof.
51 questions
For questions about user accounts that have been deleted, or the general process of account deletion.
Some changes to questions, such as edits or receiving new answers, will "bump" them back onto the site's front page where the changes can be vetted by other users.
For questions about the favorite question feature or the favorite tags feature.
50 questions
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