Cold form steel: As per the NYC DOB Code section 1704.3.1.2 cold-formed steel floor and roof decks shall be in accordance with AWS D1.3.
As per Wikipedia, Cold-formed steel (CFS) is the common term for steel products shaped by cold-working processes carried out near room temperature, such as rolling, pressing, stamping, bending, etc. Stock bars and sheets of cold-rolled steel (CRS) are commonly used in all areas of manufacturing. The terms are opposed to hot-formed steel and hot-rolled steel.
Cold-formed steel, especially in the form of thin gauge sheets, is commonly used in the construction industry for structural or non-structural items such as columns, beams, joists, studs, floor decking, built-up sections and other components. Such uses have become more and more popular in the US since their standardization in 1946.