Anybody knows if there is a documentation for NavisWorks IFC translator?

I had this experience:

- I created some Parking elements in Revit 2009; exprted them to IFC.

- Imported the IFC to NavisWorks, Parking elements showed up in the Selection Tree. But I could only select all Parking elements as one selection set (all at once, no individual selection)

- Then I imported the IFC to Solibri. No Parking object was identified. Solibri recognized them all as Objects (no name, no Family type, no IFC property-set for Parking was imported)

I want to see what's the difference between how NavisWorks translates the IFC file and how Solibri does that.

Thanks in advance