Register encompasses the variations of a language based on who is communicating to whom, through what media, and regarding what topics, though the specific definition depends on the authority. Register is indicated through changes in diction (vocabulary and word-choice), syntax, and tone among other aspects.
Registers can vary along several axes; questions tagged as register include the following:
Tenor — Questions about how English changes based on how polite or how formal your discourse is based on the situation or occasion and your familiarity or relative social status or distance with the other participants. Selected related tags: formality, politeness, political-correctness
Medium (or mode) — Questions, for example, about how spoken and written English differ, or how online and print writing differ. Selected related tags: email, headline-english, letter-writing, literary-english, poetry
Domain (or field) – Questions related to a specific subject matter (including jargon) or the specific purpose for communication. Selected related tags: business-language, legal, poetic, science, sports, technical, tech-writing, terminology