| NB: The definitions below are for words, or technical vocabulary, specific to Military Air Environment use. |
| Where a word appears in the Oxford English Dictionary (OED), the definition below is specific only to the |
| associated context and OED definitions should be used in all other usages. |
| Term | Abbreviation | Chapter Reference |
| Permanent Joint Headquarters | PJHQ |
| Description |
| Commanded by the Chief of Joint Operations (CJO), the PJHQ's primary role is to be responsible for planning and |
| executing Joint, potentially Joint, and UK-led multi-national operations, and for exercising Operational Command |
| of UK Forces assigned to combined and multi-national operations led by others |
| (http://jchq.chots.mod.uk/pjhq_web/). |