Requirements on identify of non-rooted entity instances

In **4.3 Object Attributes** we have stated:

> Resource-level instances (not deriving from [IfcRoot](http://ifc43-docs.standards.buildingsmart.org/IFC/RELEASE/IFC4x3/HTML/lexical/IfcRoot.htm)) do not have any identity, such that two instances having identical state are considered equal. For example, if an object has coordinates described by an [IfcCartesianPoint](http://ifc43-docs.standards.buildingsmart.org/IFC/RELEASE/IFC4x3/HTML/lexical/IfcCartesianPoint.htm) instance, another object with the same coordinates may have a separate instance of [IfcCartesianPoint](http://ifc43-docs.standards.buildingsmart.org/IFC/RELEASE/IFC4x3/HTML/lexical/IfcCartesianPoint.htm) or share the same instance; such difference is a matter of data storage optimization and does not imply any semantic relationship

http://ifc43-docs.standards.buildingsmart.org/IFC/RELEASE/IFC4x3/HTML/concepts/Object_Attributes/content.html

At the same time, we have implementer agreements that impose specific requirements on referencing the same instance

> In case of IfcPolyline the first and the last point may be identical, then it indicates a closed polyline. In this case they shall be identical by reference (referencing the same instance of IfcCartesianPoint.

https://standards.buildingsmart.org/documents/Implementation/IFC_Implementation_Agreements/CV-2x3-111.html

These two statements contradict one another. Any ideas?