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.
use for any questions related answer that are deleted, or in a deleting process.
for questions deleted from the site, or in a deleting process. The tag 'specific-question' should also be used when referencing a specific question.
For questions about the design of MathOverflow. This includes bug reports and suggestions about the user interface.
The question you're asking is designed to solicit opinions or best-practices on a particular topic, with the goal of reaching community consensus.
Elections are held to choose moderators for the MathOverflow site.
aimed for discussions about etiquette: how to behave on the site and the chat.
For questions about exporting and printing MathOverflow posts.
These questions are the most frequently asked and answered questions on Meta.
Proposals for new entries for the FAQ.
For questions about the flagging process, how flags are handled, etc. Flagging is the process of bringing a post to a community moderator's attention for any reason.
For questions about the 'follow questions and answers' functionality, where you receive updates about a post as if you were the post owner.
For questions about how Gravatars are fetched and displayed on the Stack Exchange network. This is not for general Gravatar support inquiries.
For issues regarding the help center of MathOverflow.
Questions about the hot questions list which appears on the main page and—truncated—on various sites in the Stack Exchange network (but not on this site), as well as its effect on MathOverflow.
For questions on usage of links at MathOverflow (both links to various parts of this site and to other sites).
For questions involving the "Ignored Tags" specified in a user's Preferences. Questions with these tags are dimmed or removed entirely from question lists.
For questions concerning using images in questions, image hosting, etc.
The "Linked Questions" sidebar is a user-generated list of related questions shown in the sidebar when viewing a question. Its content comes from questions that users have linked in the question, thei…
For questions or issues surrounding login to this site.
For questions about Markdown, a lightweight markup language used across the entire Stack Exchange network for post formatting.
Questions about the live Markdown preview of posts as they're being typed.
Questions about the Mathematics Educators StackExchange site.
Bug reports and suggestions for the MathJax system used to compile basic LaTeX code on the site.
For questions concerning MathOverflow as non-profit organization. (As opposed to questions concerning MathOverflow as a website.)
Questions related to the closely related website, https://math.stackexchange.com