MRC:
Characteristics or qualities of an item,not covered in any other requirement,which are considered essential information for one or more functions excluding nsn assignment.SUPP
Supplementary Features:
Used on data transfer center; matl: aluminum alloy casting a356-t6, grade c, class 12, per mil-a-21180, classification per mil-c-6021, class 4; all surfaces: chemical film per mil-c-5541, cl 3, using chemicals conforming to mil-c-81706; exterior: 1 coat epoxy primer per mil-p-23377, 1 coat epoxy polyamide per mil-c-22750, color black 37038 per fed-std-595