Minor 1. The text is redundant with the Figure title:
2155 Variable header non normative example
2156 Figure 3.21 shows a variable header with Packet Identifier set to 10. 2157
2159 Figure 3.19- Variable header with a Packet Identifier of 10, Non normative example
2. Minor edit - The context is set in the first sentence so the "SUBSCRIBE pakcet payload" does not need to be repeated in the second sentence:
2173 The payload of a SUBSCRIBE Packet contains a list of Topic Filters indicating the Topics to which the
2174 Client wants to subscribe. The Topic Filters [in a SUBSCRIBE packet payload] MUST be UTF-8 encoded
2175 strings as defined in Section
Suggestion:
The Topic Filters MUST be UTF-8 encoded.
3. Missing comma
2179 characters[,] it MUST reject any Subscription request whose filter contains them
4. Redundant not used and reserved
2210 Bits 6 and 7 of the Subscription Options byte are not used, and are reserved for future use.
Suggestion:
Bits 6 and 7 of the Subscription Options byte are reserved for future use.
5. "if" rather than "is"
2188 ... It is a Protocol Error [is] the