I am the assigned Gen-ART reviewer for this draft. The General Area Review Team (Gen-ART) reviews all IETF documents being processed by the IESG for the IETF Chair. Please treat these comments just like any other last call comments. For more information, please see the FAQ at . Document: draft-york-p-charge-info-08 Reviewer: Ines Robles Review Date: 2018-08-13 IETF LC End Date: 2018-08-13 IESG Telechat date: Not scheduled for a telechat Summary: This document requests to IANA, the registration of a SIP P-header ,P-Charge-Info, as a "grandfathered case". Since the draft states that P-Charge-Info has been in deployment since prior to 2007 and pre-dates RFC 5727 (which deprecates new usage of "P-" header fields). It is aligned what is mentioned in the IANA web page [1] " ...Existing "P-" header field registrations are considered grandfathered, but new registrations of Informational header fields should not begin with the leading characters "P-" (unless the "P-" would preserve compatibility with an pre-existing unregistered usage of the header field, at the discretion of the Designated Expert)." I understand that this case is a pre-existing unregistered usage of the header field. This draft is Informational. RFC 5727[2] mentions: " ...the registration of SIP header fields in Informational RFCs, or in documents outside the IETF, is now permitted under the Designated Expert (per [RFC5226]) criteria". I understand that a designated Expert agreed on this. I believe the draft is technically good. This document is well written and clear to understand. Major issues: No major issues found. Minor issues: -In Introduction: I would add some examples of carriers, application providers and equipment in here. "Several carriers, application providers, and equipment providers have been using the P-Charge-Info header field since at least 2007 as a simple mechanism to exchange this billing identifier." Nits/editorial comments: Not found. Thanks for this document, Ines. [1] https://www.iana.org/assignments/sip-parameters/sip-parameters.xhtml#sip-parameters-2 [2] https://tools.ietf.org/html/rfc5727#section-4