Some editorial comments:
Abstract
This document defines the formal Uniform Resource Name (URN)
Namespace Identifier (NID) for Ad-ID Identifiers.
It would make the abstract more informative to say 'the formal ... URN
... NID "adid" for Ad-ID Identifiers'.
Introduction
The Abstract expands on "all media platforms (over the air, on-line,
over the top, mobile, place based)" whereas the Introduction does not.
It seems to me that if the expansion is sufficiently valuable to put in
the abstract, it is valuable enough to put in the Introduction.
However, I suspect the better usage is to put the expansion in the
Introduction only, as it is not needed to make the Abstract
understandable, even to a naive reader (like me).
Ad-ID Identifiers are unique codes for each advertising asset
digitally, and applies that code to all media.
This sentence has grammar problems. "digitally" is an adverb, and so
must modify "are", but that does not make sense. Should the text be
"are unique codes for each digital advertising asset"?
Also, the subject of "applies" is unclear. Should the text be "... and
are applied to all media"?
2. URN Namespace Definition Template
The non-terminals "alpha" and "digit" seem to be references to the
definitions in RFC 5234. But in 5234, they are spelled "ALPHA" and
"DIGIT". If that is intended, these must be all-caps.
Dale