With Create Steel Stiffener you can add the stiffener part to the steel, drag the command to the chosen end of the steel.
From the combobox it is possible to choose the section of the stiffener profile between: Equal, Sharp corners, Chamfered corners, Filled corners. And you can choose if Create Attach Points for link the stiffener to the steel.
The bottom section of the dialog contains the items useful to set the information related to the component. The section is divided in two parts: BOM Information and Custom Information.
BOM Information section contains the same options of the other components, but there is this option more:
User Name Prefix - This check button controls the enable state of the text item placed on the right. If this button is checked, any string placed in the text item will be used as prefix of the User Name.
For a detailed explanation of the other items see BOM information