M2M needs definition (or an acronym list entry)

M2M may not be a clear term/acronym to some readers.
(a) M2M is used with definition (but not reused) in the Abstract
(b) M2M is used with definition in the Introduction, then reused as "M2M Web"
(c) M2M is NOT in the definition of terms. There is no acronym list
(d) M2M is used extensively in 1.8 and 2, but not later.

Consider what "M2M" adds to the discourse. It is not clear to me that it adds much, as most communication we speak of is M2M. If the intent is to separate communication and interactions that are initiated by machine detection (e.g. sensors, state changes) rather than humans, that should be made clear.

Perhaps a rewrite of the non-normative quickstart (e.g. around lines 173-180) would be helpful.

If this is standard terminology in some universe, it should be defined and referenced.