ModelReference and ModelNumber properties need further distinction in their description

[Moult]

The two properties sound very similar to a non-expert. It would be good for @billeast to help provide a sentence distinguishing the two:

http://ifc43-docs.standards.buildingsmart.org/IFC/RELEASE/IFC4x3/HTML/lexical/Pset_ManufacturerTypeInformation.htm - ModelReference http://ifc43-docs.standards.buildingsmart.org/IFC/RELEASE/IFC4x3/HTML/lexical/Pset_ConstructionOccurence.htm - ModelNumber

[billeast]

Suggested changes to definitions, please feel free to wordsmith:

http://ifc43-docs.standards.buildingsmart.org/IFC/RELEASE/IFC4x3/HTML/lexical/Pset_ManufacturerTypeInformation.htm - ModelReference

"The designator of the product type model (or product line) as assigned by the product's manufacturer. Also, the ElementType model (or product line) designator identified during the construction submittal process. This is not the designator identified as "Basis of Design" on product schedules."

http://ifc43-docs.standards.buildingsmart.org/IFC/RELEASE/IFC4x3/HTML/lexical/Pset_ConstructionOccurence.htm - ModelNumber

"The designator for an individual manufactured product instance as assigned by the manufacturer at the time of product procurement. Also, the designator found on the installed product's shipping manifest and nameplate. This designator is typically a further specification of ElementType Pset_ManufacturerTypeInformation.ModelReference."