IfcRoot GlobalId "optional" conflict between IFC 4x2 EXP and XSD schemas

[devonsparks]

Apologies in advance if this is filed in the wrong location:

It looks like there's a conflict in the EXPRESS and XSD specs of IFC 4x2 as to whether IfcRoot's GlobalId is optional:

XSD says it is:
https://standards.buildingsmart.org/IFC/DEV/IFC4_2/FINAL/XML/IFC4x2.xsd

    <xs:complexType name="IfcRoot" abstract="true">
    <xs:complexContent>
    <xs:extension base="ifc:Entity">
    <xs:sequence>
    <xs:element name="OwnerHistory" type="ifc:IfcOwnerHistory" nillable="true" minOccurs="0"/>
    </xs:sequence>
    <xs:attribute name="GlobalId" type="ifc:IfcGloballyUniqueId" use="optional"/>
    <xs:attribute name="Name" type="ifc:IfcLabel" use="optional"/>
    <xs:attribute name="Description" type="ifc:IfcText" use="optional"/>
    </xs:extension>
    </xs:complexContent>
    </xs:complexType>

EXPRESS says it isn't:
https://standards.buildingsmart.org/IFC/DEV/IFC4_2/FINAL/EXPRESS/IFC4x2.exp

    ENTITY IfcRoot
    ABSTRACT SUPERTYPE OF (ONEOF
        (IfcObjectDefinition
        ,IfcPropertyDefinition
        ,IfcRelationship));
	       GlobalId : IfcGloballyUniqueId;
	       OwnerHistory : OPTIONAL IfcOwnerHistory;
	       Name : OPTIONAL IfcLabel;
	       Description : OPTIONAL IfcText;
    ...
    END_ENTITY;`

What's the right channel to have this addressed? Thanks!

[jmirtsch]

This is the right place to raise the issue, but to get a broader buildingSMART perspective/discussion, I've opened a forum post on this issue. https://forums.buildingsmart.org/t/xsd-optional-attributes/1641