Pset_ManufacturerTypeInformation.ModelReference and Pset_ConstructionOccurance.ModelNumber seem to be the same

Reading back to the draft AOH-BSEM spec, it seems as though the difference is that Pset_ManufacturerTypeInformation.ModelReference is the manufacturer's "model number / reference" whereas Pset_ConstructionOccurance.ModelNumber is the "occurrence's installed model number". This nuance seems to be lost in the spec.

Compare the draft AOH-BSEM specification's definitions of Pset_ManufacturerTypeInformation.ModelReference and Pset_ConstructionOccurance.ModelNumber. Confirm whether the manufacturer's reference and the occurrence's installed model number should be distinguished, then document the agreed clarification in the specification.

Written by the indexing model from the issue text.