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-ietf-ntp-using-nts-for-ntp-22 Reviewer: Dan Romascanu Review Date: 2020-02-26 IETF LC End Date: 2020-02-28 IESG Telechat date: Not scheduled for a telechat Summary: Ready with one minor issue to be discussed. A very clear, well written, nicely organized document. Major issues: Minor issues: 1. The tables in Sections 7.6, 7.7, 7.8 state that all undefined values in the registries start immediately after the values defined by this document with 'Reserved for Private and Experimental Use'. What about future extensions in future versions of the document? Would not it be better to leave a range for future extensions and start the values for private and experimental use farther in the total spaces? Nits/editorial comments: 1. In the (very useful) Appendix A for Terms and Abbreviations, there are a few abbreviations usually considered part of the shared basis terms in IETF documents (like TCP, UDP, IANA, ...)