"^^c:\databases\user" is an implied namespace based on the directory name. 

You can enter an implied namespace yourself by issuing something like >ZN "^^"_$ZU(12,"USER")

Once you have entered an implied namespace, it looks like it appears in the array returned by ListAll()

I suspect that if you load classes, routines or globals in the Management Portal and choose "Database" instead of "Namespace" in the Explorer that you will then be making use of an implied namespace.