The status Topic has the form:

<Prefix>/<Encoding>/status/<PublisherId>

The <PublisherId> Topic level is the PublisherId for the application sending the messages.

The messages are instances of the Status MessageType (see 7.2.2).

A Publisher that is exclusively using a PublisherId shall register a Status message as an MQTT Will message when it creates the connection to the MQTT Broker. This message is sent automatically if the Publisher loses its connection with the MQTT Broker. The IsCyclic shall be FALSE in this case. The PubSubState value of the Will message shall be Error.

If a single MQTT client connection has multiple PubSubConnections (like for different encodings), not more than one PubSubConnection can register a Status message as MQTT Will message. All other PubSubConnections shall use cyclic Status messages.