How do you describe the supplier of a resource?

If an organisation supplies a resource (e.g. materials), how is this organisation related to the IfcResource?

Here are two snippets from the spec which seem promising, but neither seem explicit enough in their descriptions to give me confidence.

A resource may be assigned to an actor by IfcRelAssignsToActor where RelatingActor refers to an IfcActor and RelatedObjects refers to one or more IfcConstructionResource or other objects. Such relationship indicates the actor responsible for allocating the resource such as partitioning into task-specific allocations, delegating to other actors, and/or scheduling over time. Note that this assignment does not indicate the person or organization performing the work; that is indicated by IfcRelAssignsToResource. The actor responsible for the resource may or may not be the same as any actor(s) performing work.

… and …

A resource may have assignments of other objects using IfcRelAssignsToResource where RelatingResource refers to the IfcConstructionResource and RelatedObjects refers to one or more objects such as IfcActor or IfcProduct subtypes. This relationship indicates specific objects assigned to fulfill resource usage.

The first option seems to be the actor responsible for resource allocation. This is not the same as a supplier. The second option seems to be the actor responsible for carrying out the work that consumes the resource. This is definitely not the same as a supplier.

If I had to pick, I’d choose the first.

Note that in both options, IfcActor may have a role set to SUPPLIER.