Concepts are represented by a rectangle, containing the name of the concept as shown below.
Figure 4.1-1: Concept element
The name used must be the concept's fully specified name or a synonym.
Optionally the definition status of a concept may be represented. Concepts that are fully defined may be represented using a double line border as shown below:
Figure 4.1-2: Defined concept element
A rectangle with a single border is assumed to be primitive unless explicitly noted otherwise or it is clear in context (e.g., diagramming during a whiteboard discussion).