MRC:
Those unusual or unique characteristics or qualities of an item not covered in the other requirements and which are determined to be essential for identification.FEAT
Special Features:
The general requirement of mil-w-21157 class 4 apply except as folows: welders and welding operators shall be qualified to mil-std-248 (navy) dated 17 june 1958 and change notice 1 dated 27 august 19583 use welding material aws a5.18cl, e705-18. Interpret dimenstion, symbols etc in accordance with listed documents as follows abreviations mil-std-12 dimensions, tolerances and geometric symbols-usa si y14.5-1966.
