When you select Open from the File menu and then select a section library (cfsl) file, the Open Library Section window appears. A section library is a collection of section files organized by section type. CFS includes libraries of some manufacturers' products and some industry standard shapes (SSMA, LGSI, HUD, AISI). These libraries are installed in a folder called CFS Files under Documents.
In this window, first select the section type you want to use. Then in the section list, select the name of the section you want to open and press the Open button. Once a library section is opened, you may work with it like any other section. You may edit the section and perform computations. The only difference is you cannot save it back to the library, but you can save it as its own section file.
If you are not familiar with the terminology used for the section types or the section names, contact the source shown at the top of the window for further information. To create a library created for your own use, or for distribution to other CFS users, refer to Library Builder on the Tools menu.