This is a list of initials, acronyms, expressions, euphemisms, jargon, military slang, and sayings in common or formerly common use in the United States Air Force. Many of the words or phrases have varying levels of acceptance among different units or communities, and some also have varying levels of appropriateness (usually dependent on how senior the user is in rank). Many terms also have equivalents among other service branches that are not acceptable amongst Marines, but are comparable in meaning. Many acronyms and terms have come into common use from voice procedure use over communication channels, translated into the NATO phonetic alphabet, or both.