MRC:
An indication of the weapon/s/ for which the item is designed.AHVQ
Weapon For Which Designed:
Howitzer, cannon m2a1 and howitzer, cannon m2a2 and howitzer, cannon m4 and howitzer, cannon m4a1 and howitzer, cannon m49
MRC:
A feature of the item of supply which must be specifically recorded when the reference number covers a range of items.ZZZY
Reference Number Differentiating Characteristics:
As differentiated by cartridge case material, fuze type, fuze model number, fuze delay time, propellant characteristic markings, package model number, unit package type, unit package quantity, dod ammunition code