| 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 |
| Special Instruction (Technical) | SI(T) | Chap 10.5.1 |
| Description |
| An instruction, issued by the PT, that gives instructions to undertake a work package to repair or prevent a |
| potential fault. There are 4 types of SI(T): STI, SI, UTI and RTI. |