posted 09-05- 03:38 AM
I'm no English expert
, but Pachy ya sort of correct. In the Aussie Army staff duties manual
we describe contractions and abbreviations.An example of a contraction would be Mark = Mk, here only the initial letter is in upper case.
An abbreviation would be Fighter-Bomber = FB, here the first letter of each word is in upper case.
(or was it the other way around....damm where's that manual
)
With regard to the original question, I believe none are correct 
What's missing is the description of if it was a standard model or specialised, eg:
Standard = F
Low level ops = LF
High altitude ops = HF
Fighter/Recon = FR
Photo/Recon = PR
With this in mind, the correct term would be:
Spitfire F Mk.Vb (if it was standard)
Reference:
'Spitfire, Mustang and Kittyhawk in Australian Service'
By Stewart Wilson
ISBN 0 9587978 1 1
Aerospace Publications Pty Ltd
Cheers,
------------------
AGAS 5
=RAAF75=
[This message has been edited by AGAS - 5 (edited 09-05-2001).]