There is no unified regulation or agreement on the classification methods of cold-formed steel products.
Generally speaking, cold roll formed steel profiles can be classified  by the sectional shape characteristics of the products.
By the section shape, they can be roughly divided into the following three categories: open section section, closed section section and wide section.
1. open section section
Example: Door Frame Profile, C-Punrlin, Racking Upright, Racking Beam
2. closed section section
Example: Box Beam, Downspout
3. wide section
Example: Roofing Panel and Wall Siding, Decking