With older aircraft, the export designation is usually simply a translation of the Chinese designation (Q-5 = A-5, JJ-6 = FT-6 etc). Interestingly, the subverion for export models is generally given by alphabetical suffixes while PLAAF designations use (again generally) Roman numerals. For example, the H-6IV is in Iraqi service as the B-6D, and the Q-5III serves with the Pakistani airforce as the A-5C.

I think this system in some form might very well apply to the tank designations you've given (Type 80III is PLA, Type 88C is export, etcetera).

Regards,

Arthur Hubers