Minor 1. line 22 These sentence "These characteristics make it ideal for use in constrained environments, for example, but not limited to:" reads awkwardly. How about a splitting it into two, , "These characteristics make it ideal for use in constrained environments,. These include environments:
2. Line 24 uses the word "unreliable". When writing the charter we tried to avoid that word, as it has negative connotations if you are a telco. Actiually the charter provides the following overall summary..
"Providing a lightweight publish/subscribe reliable messaging transport protocol suitable for communication in M2M/IoT contexts where a small code footprint is required and/or network bandwidth is at a premium." which we could use somewhere on this page.
3. Line 29. Add words "The use of" at the start
4. Line 32 explicitly mentions TCP/IP.
5. Line 35. This refers to QoS 0 as "At most once" but then goes on to say that Duplication can occur... This is actually a wider issue as this wording appears elsewhere in the spec
6. Line 43. I suggest deleting the words "using the Last Will and Testament feature" , since we don't use this term anywhere else.