MRC:
The specification,standard,or manufacturers reference,and the classification designation,such as class,condition,temper,and the like,that identifies the material.MDCL
Material Specification:
Mil-s-5059, type 301 federal specification 1st material response or mil-s-5059, type 302 federal specification 2nd material response or mil-s-5059, type 304 federal specification 3rd material response or mil-s-5059, type 316 federal specification 4th material response or mil-s-6721, comp ti federal specification 5th material response