220.127.116.11.2.1.2 Receiving a PARTNERTM_PROPAGATE_MTAG_PHASE0REGISTER Message
If the connection state is Active:
Otherwise, if the connection state is Phase Zero:
Set the connection state to Phase Zero Registration During Phase Zero.
Signal the Create Phase Zero Enlistment event on the Core Transaction Manager Facet with the Enlistment object that is referenced by this connection.
Otherwise, the message MUST be processed as an invalid message as specified in section 3.1.6.