Definition from buildingSMART: An IfcPropertySetDefinition
is a generalization of property sets, that are either:
Dynamically extendable properties, they
define properties for which the IFC model only provides a kind of "meta
model", to be further declared by agreement. This means no entity
definition of the properties exists within the IFC model. The
declaration is done by assigning a significant string value to
the Name attribute of the entity as defined
in the entity IfcPropertySet and at each subtype of
IfcProperty, referenced by the property set.
Statically defined properties, they
define properties for which an entity definition exists within the IFC
model. The semantic meaning of each statically defined property is
declared by its entity type and the meaning of the properties is
defined by the name of the explicit attribute.
The subtypes of the IfcPropertySetDefinition
are either the dynamically extendable IfcPropertySet,
or all other statically defined subtypes.
New Entity in IFC Release 2x
|| Reference to the relation to one or many objects that are characterized by the property definition. The
reference may be omitted, if the property definition is used to define a style library and no instances,
to which the particular style of property set is associated, exist yet.
|| The property style to which the property set might belong.