Automatically created PV names in Assembly

Trying to understand details of generated PV names.

Looking at

assembly volume instance number? The number of the assembly within the GDML file, starting at 0/1?
assembly volume imprint number ??
name of the placed logical volume in the assembly - Okay think I understand that one.
index of the associated logical volume - Index within the Assembly? or GDML file? starting at 0/1?

Thanks