Grademark.

CFR · 2024-01-01 · US · Title 7

A grademark normally consists of three symbols which indicate group, quality, and color. A letter is used to indicate group, a number to indicate quality, and a letter or letters to indicate color. For example, C2F means Lugs, second quality, and tan color.

official document · source cfr-2024 · id 7:§ 29.3028