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 head material, head load type, chemical corps symbol, filler material, head type, filler material weight, head model number, nose fuze, nose fuze model number, base fuze, supplementary charge, motor size designation, motor model number, motor propellant grain quantity, motor propellant material, motor propellant grain model number and motor propellant grain weight