MRC:
The lettering or design on the item,or that is the item.AYBM
Inscription:
Partial legend gun, artillery, sp 20 mm, m163 u.S.A. Darcom nsn mfd by veh ident no. Crew 4 men including driver, max towed load operators manu
MRC:
The specification,standard,or manufacturers reference,and the classification designation,such as type,class,grade,and the like,that identifies the surface treatment material.STDC
Surface Treatment Specification:
Mil-a-8625, type 2, class 2 military specification single treatment response