Hello there; By defining C and Z sections as purlin as cold rolled profiles in the program, you can design according to AISI S100-12. Sigma sections are not available in the library. If you want to define it, you should create the cross section of the plan screen with the line command, select all the lines and use the right button - convert - polygon section command. In this way, you can obtain analysis results and drawings of the sections you define, but you cannot design. Good work.