Questions about standard words and phrases used by pilots and ATC in radio communications
In aviation, standard radio (formally, radiotelephony) phraseology is used to ensure pilots worldwide are able to communicate in an unambiguous manner with Air Traffic Control.
The most well-known part of standard aviation radio phraseology is the use of the 'phonetic alphabet' for letters and numbers: Alpha, Bravo, Charlie etc. This alphabet is not unique to aviation and is used for other activities where it's important to be able to communicate letters or spell words clearly.
ICAO document 9432 (apparently not available online) describes the standard phraseology which forms the basis of aviation radio communications worldwide. The ICAO phraseology is not exhaustive and at local level additional phraseologies can be in use. For example, the FAA issues a Pilot/Controller Glossary that lists all standard words and phrases to be used by pilots and ATC in the US and is broadly aligned with ICAO standards.
Use this tag for questions about words, phrases and abbreviations used in aviation radio communications. More general questions about words, phrases or definitions should usually be tagged terminology instead.