A quick Tip and Trick when working with Steel models between ASD and Revit Structure.
When transferring a steel model from Revit Structure to ASD (AutoCAD Structural Detailing) your standard sections will be mapped without any problems. However, if you need to create any bespoke sections then you will need to generate these first in ASD and then the sections will appear in the Revit Structure content generator.
In the above example, you can see the custom sections shown in the Revit Content Generator (Found on the Extensions Ribbon).
Here is the same profile in ASD.
Hope this helps,