Clarifications needed on commonalities or relationships between IfcLightFixture and IfcLamp

[Moult]

Revisiting this as we are working on mapping data required by state government to IFC.

There are lots of ambiguities with IfcLightFixture and IfcLamp - for example, how are they related to one another? Many people don't bother modeling every single bulb, and LED can be integrated into the light fixture (luminaire). In this case, can I propose:

1. Clarify that the relationship between IfcLightFixture and IfcLamp is IfcRelNests, given that the parent may have its own representation and there is a clear fixture hole / attachment point.
2. Add a LampType property to Pset_LightFixtureCommon of data type IfcLampTypeEnum, that way you can easily specify the type of lamp without modeling every single bulb (or you might not even know yet how many bulbs).

https://forums.buildingsmart.org/t/proposal-for-documentation-to-explicitly-mention-relationships-between-ifclightfixture-and-ifclamp/3693

https://forums.buildingsmart.org/t/ifclightfixture-or-ifclamp/4276/2