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 about the measurement of a user's contributions to the site, and the extent to which the community "trusts" that user with extra privileges.
Questions about the user interface elements (inputs, buttons, checkboxes, etc.) that make up Language Learning SE. For questions about the design of elements, use the design tag.
Questions about the process of editing, how edits work, and other general inquiries about the edit system.
Questions about the built-in search functionality of this site.
Questions about identifying and closing questions that are duplicates of another question.
Questions related to the norms and standards of accepted behaviour and politeness on Language Learning Stack Exchange.
Questions related to the user interface elements and e-mails that notify users of events on the site (answers to a question you asked, comments, responses in the chat, ...).
Questions about users (and user accounts) on LL SE. For questions specifically about user accounts, use the tag `user-accounts`.
Questions related to OpenID, an open standard that allows users to log in to many websites with a single set of third-party credentials.
Questions about (the process of) migrating (off-topic) questions from Language Learning Stack Exchange site to another Stack Exchange site, or in the opposite direction.