User specified dimensions for a fixed list of known section types in ISM are known as Parametric Sections. The following types of sections are supported as Parametric sections in ISM: C shapes (Channels), Double L shapes (Double Angles), Hollow Circle shapes (round tubes), Hollow Rectangle shapes (Rectangular Tubes), I shapes (Wide Flange), L shape (Angles), Solid Circles, Solid Rectangles, T shapes (Tees).

For instance, solid circles and solid rectangles are not delivered in Bentley Structure Property Catalog. They are exported to ISM as parametric sections.