SysML1.0:
The Block stereotype extends Class, so it can be applied to any specialization of Class, including Association Classes. These are informally called “association blocks.” An association block can own properties and connectors, like any other block. Each instance of an association block can link together instances of the end classifiers of the association.
To refer to linked objects and values of an instance of an association block, it is necessary for the modeler to specify which (participant) properties of the association block identify the instances being linked at which end of the association The value of a participant property on an instance (link) of the association block is the value or object at the end of the link corresponding to this end of the association.
Participant properties can be the ends of connectors owned by an association block. The association block can be the type of multiple other connectors to reuse the same internal structure for all the connectors. The keyword «participant» before a property name indicates the property is stereotyped by ParticipantProperty. The types of participant properties can be elided if desired. They are always the same as the corresponding association end type.
