PSP - Pierced steel planking
FSP - Forward Staging Post
ADLS
- Air Delivery Letter Service
ASP - Air Stores Park
AM Tech Int - Air Ministry Technical Intelligence(?)
MTLRU - Mechanical Transport Light Repair Unit
EFI - Expeditionary Forces Institute
BIS - Bulk Issue Stores
MDS - Military Dental Services(?)
AMES - Air Ministry Experimental Station (code for mobile radar)
C & D Unit - Concealment and Display Unit (they created dummy aircraft and carried out camouflage)
CAEU - Casualty Air Evacuation Unit
EDIT - blimey, one starts typing and everyone posts before me 