Dear all,

I am the assigned reviewer for the Applications and Real Time Area Review Team (ART-ART).

Nits/editorial comments:

One minor comment is that since this document sets a registry with a limited set of cost-modes (for now "numerical" and "ordinal") that require IANA registration anyways, why not assign some 8-bit codes ("0x0, 0x1") to save space on the wire.? Probably this has already been discussed somewhere in the WG, so I apologize if I am way off on this.

Another minor comment is that RFC7285 defines variations of a JSON they use in now few different locations in the document, section 10.1, section 10.6, section 10.8.2 and after this document is approved also on section 10.5. To make transparent to the that they are different I would consider writing a line on section 3.2 saying that neither the '.' separator nor the the at sign ('@') are allowed.

There is an extra space on 3.2: U+0041 -U+005A
Should be: U+0041-U+005A

There is a typo on 3.2: ('_', +005F)
Should be: ('_', U+005F)