query_context
    type:       $SCA_QUERY_CONTEXT
    access:     read/write
    mechanism:  by reference

    An SCA query context that is to describe a specific entity.

 entity_handle
    type:       $SCA_HANDLE
    access:     read/write
    mechanism:  by reference

    An SCA entity handle that describes the entity that the newly
    defined query context is to match.