A profile diagram operates at the metamodel level to show stereotypes as classes with the <<stereotype>> stereotype, and profiles as packages with the <<profile>> stereotype.[1] The extension relation (solid line with closed, filled arrowhead) indicates what metamodel element a given stereotype is extending.
The profile diagram didn't exist in UML 1. It was introduced with UML 2 to display the usage of profiles. Before its introduction, other diagrams had been used to display this issue.[1]
^ abBernd Österreich (2009). Analyse und Design mit UML 2.3 - Objektorientierte Softwareentwicklung (in German) (9 ed.). Munich: Oldenburg. p. 334. ISBN978-3-486-58855-2.
Christoph Kecher: "UML 2.0 - Das umfassende Handbuch" Galileo Computing, 2006, ISBN 3-89842-738-2
