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:
Size 4 in. Valve kit consisting of, 2 - no. 2, gasket, cover plate, 1 - no. 3, spring, main valve, 1 - no. 8, spring, check valve, 2 - no. 11, spring, main and check valve, 2 - no. 14, disc, upper and lower relief valve, 1 - no. 17, spring, relief valve, 1 - no. 18, gasket, clamp-bolt, 1 - no. 21, diaphragm, 1 - no. 25, gasket, relief valve housing