Naming Naming is something that occurs in a number of places in XTM and there is a need to have a common naming mechanism. Names can be assigned to different aspects of the model by creating a naming association between the name resource and the topic map construct to be named. Scope Scope is modelled as a topic associated between topics that are the scoping topics and other end points that are the topic map constructs to whom scope is applicable, occurrences, names and association roles. The class instance relationship is the clarification of type from ISO13250. ClassInstance is modelled as a subclass of topic association where the end points subclass assoc role in order to describe the semantic that the topics play in the classinstance association.
Public subjects are still reliant on prose and have no model to guide implementations.
By capturing the intent formally there is no opportunity for misinterpreting the intent. Public subjects are a great mechanism for user defined extensions but are not suitable for capturing the core model. Here it is modelled as a subclass of topic association and the roles subclass association roles, again to capture the semantic intent of the model. These few UML diagrams capture the essential model of topic maps in a clean manner. In the next section an example is given that uses this model to create a XTM instance diagram from an syntax fragment.