I have reviewed this document as part of the Operational directorate's ongoing effort to review all IETF documents being processed by the IESG.  These comments were written with the intent of improving the operational aspects of the IETF drafts. Comments that are not addressed in last call may be included in AD reviews during the IESG review.  Document editors and WG chairs should treat these comments just like any other last call comments.

PASSporT (RFC8225) defines a method for creating and validating a token that cryptographically verifies an originating identity or, more generally, a URI or telephone number representing the originator of personal communications.  This document extends PASSporT to also support cryptographic signing of the 'SIP Resource Priority' header field indicating resource prioritisation for the communication, to mitigate abuse of that field.  

The document is quite well written, but includes some repetition of material, in particular in the introduction, and a few minor grammatical issues.

The document is Ready for publication, with minor nits.

Nits:
* Tidy up or simplify the introduction text, which is unnecessarily verbose.
* Check the text for grammatical issues, especially use of the indefinite article.