[Nadia]

234sqn ( ..requires 234sqn.tga and 234sqn.mat as well.. )
This format seems like the original IL-2.
more...
...
234sqn
238Squadrontc
240Squadronmaritime
240Squadronmaritimefe
240Squadronmaritimeuk
242Squadronfe
243Squadron
243Squadrontc
249Squadron
257Squadron
258Squadronlate
258Squadronmid
259Squadronmaritime
261Squadronfe
262Squadronmaritime
264Squadron
265Squadronmaritime
266sqn
266Squadron
267Squadrontc
273Squadronlate
326sqn
340sqn
341sqn
342sqn
501Squadron
601Squadron
603Squadron
605Squadronfe
607Squadronfe
609sqn
60Squadron
610Squadron
615Squadron
616sqn
628Squadronmaritime
681Squadron
684Squadron

118thSquadron
400thSquadron
401thSquadron
402thSquadron
...

th used appear to be Canadians squadrons inside RAF...

...
400Squadron
401Squadron
402Squadron
403Squadron
...
These are for ca as a country on it own !

All the above are lines in regiments.ini for activation... forgotten_countries, which includes what is there before anyway. Hope this helps.

Note that format/slot 250Squadron may have been taken by another country
... that's why names above vary so much...
sqn have been used for Thailand !
Note: some squadrons appear more then once, like old IL-2 and new way to represent them...: early Il2 had Squadron's Insignias on planes; the later none.
266sqn
266Squadron

few more I found:

RAF_No112SQN
RAF_No134SQN
RAF_No303SQN
RAF_No310SQN
RAF_No312SQN
RAF_No320SQN
RAF_No326SQN
RAF_No331SQN
RAF_No340SQN
RAF_No486SQN
RAF_No501SQN
RAF_No601SQN
:OO