AM Form 1180 Codes

Chaps
A friend is trying to understand/decipher the codes on the top of a Air Ministry Form 1180 for a Wellington mishap. The codes are:-

FM
ABOK
PCM
PCN
ETP
VOK
AOK
XOK
WOK

I think ETP is Empire Training Program/Plan
PCM could be post crash management
ABOK could be Oakey or Aboukir?
Any ideas or help gratefully received!