N.Y.C. Admin. Code § 27-601: § 27-601 Identification.

(a) Masonry units. Masonry units shall be clearly identified to show the grade of the unit and the compressive strength where called for on the plans.

(b) Metal reinforcement. Reinforcing bars shall be rolled so as to identify the grade of steel and the size. Bundles and rolls of cold-drawn steel wire or welded wire fabric shall be tagged so as to identify the type and grade of steel and the size.