IfcElementAssembly issue on Rail domain components

The **IfcElementAssembly** consists of its components. It does not necessarily need to have an explicit geometric representation, but in most railway components, this assembly must have specific properties.
The problem is that when you export an assembly to IFC, its global properties disappear, leaving only the properties of its individual components. This is very inconvenient.
Apparently, using an **IfcRelNests**-type assembly resolves the issue, but this constraint is not explicitly stated in the standard’s entities, which causes problems for software vendors during implementation. We are encountering this issue with IFCRail objects (catenaries, tracks, signaling).
Please address this issue as soon as possible, as it creates a lot of confusion in IFC models, which are difficult to use in the railway industry.
Best Regards

Start by reviewing the IFC4.x specification entries for IfcElementAssembly and IfcRelNests, then compare how IFCRail assemblies such as catenaries, tracks, and signaling components are represented. Done means the standard clearly states how an assembly's own properties and component relationships must be represented, resolving the reported export ambiguity.

Written by the indexing model from the issue text.