VVS Squadron Designations

[Marabekm]

Afternoon all. I am looking for some help understanding the VVS squadron designations.

Here is what I know:
IAP: Fighter Aviation Regiment
IAD: Fighter Aviation ______
IAK: Fighter Aviation _______

Don't know what D and K are. Its something to do with the unit size I am guessing?

BAP: Bomber Aviation Regiment
TBAP: Heavy Bomber Aviation Regiment
BAD: Bomber Aviation _________
NBAP: Night? Bomber Aviation Regiment
LBAP: _____ Bomber Aviation Regiment
SBAP: _____ Bomber Aviation Regiment
BBAP:______ Bomber Aviation Regiment
DBAP: The D here is different from the D at the end I think. _______ Bomber Aviation Regiment.

ShAP: Assault Aviation Regiment
RAP: Reconnaissance Aviation Regiment
ORAP: Independent Reconnaissance Aviation Regiment

MTAP: _______ _______ Aviation Regiment
SAD: _____ Aviation _____
ZIAP: ______ ______ Aviation Regiment

So, who can help me fill in the blanks?

The first letter, or 2 letters, appears to be aircraft type
The seems to designate Aviation
The last letter seems to be something to do with the unit size.