I have reviewed this document as part of the security directorate's
ongoing effort to review all IETF documents being processed by the IESG.
These comments were written primarily for the benefit of the security
area directors.  Document editors and WG chairs should treat these
comments just like any other last call comments.

This document does not raise any particular security issues so
the security considerations section of the document is adequate.
Subsequent documents that define values and sub-registries within
the nena namespace may need more detailed discussions of security
considerations.

I did notice one non-security issue. In the Declaration of syntactic
structure in section 2, the structure the structure is given as
{NENAclass}:ClassSpecificString}. I don't know why curly braces are
being used here but I suppose they are intended to indicate that
NENAclass and ClassSpecificString are variable strings. If so,
there should be an opening curly brace before ClassSpecificString.

Thanks,

Steve