Francois Normandin

If a Server receives an UNSUBSCRIBE packet that contains multiple Topic Filters it MUST handle that packet as if it had received a sequence of multiple UNSUBSCRIBE packets, except that...

Even where no Topic Subscriptions are deleted, the Server MUST respond with an UNSUBACK.

The Server MUST respond to an UNSUBSUBCRIBE request by sending an UNSUBACK packet. The UNSUBACK Packet MUST have the same Packet Identifier as the UNSUBSCRIBE Packet.

If a Server deletes a Subscription It MUST complete the delivery of any QoS 1 or QoS 2 messages which it has started to send to the Client.

If a Server deletes a Subscription It MUST stop adding any new messages for delivery to the Client.

The Topic Filters (whether they contain wildcards or not) supplied in an UNSUBSCRIBE packet MUST be compared character-by-character with the current set of Topic Filters held by the Server for...

The Payload of an UNSUBSCRIBE packet MUST contain at least one Topic Filter. An UNSUBSCRIBE packet with no payload is a protocol violation.

The Topic Filters in an UNSUBSCRIBE packet MUST be UTF-8 encoded strings as defined in Section 1.5.3, packed contiguously.

Bits 3,2,1 and 0 of the fixed header of the UNSUBSCRIBE Control Packet are reserved and MUST be set to 0,0,1 and 0 respectively. The Server MUST treat any other...

The order of return codes in the SUBACK Packet MUST match the order of Topic Filters in the SUBSCRIBE Packet.