Idd:IfdPropertyTypeEnum

The IfdPropertyTypeEnum enumeration is the enumeration representing whether a property is used as a defining property or as a specifying proporty. This enumeration is kept in a seperate schema.

Enumeration items:
 * DEFINING - for defining properties, which are part of the formal definition of an IfdConcept
 * SPECIFYING - for specifying properties, used in a specification of an IfdConcept