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. [General summary] This document is ready. [Topic of this draft] This draft talks about the UDP Usage Guidelines and replaces RFC 5405 (BCP). It talks about how to use UDP, especially it pays attention to the fair use of the network resourced and talks a lot on congestion control. The RFC 5045 focuses on unicast case, but this bis document talks about multicast, (anycast, broadcast, )and IP tunneling cases. The content is useful, and I hope to see this draft to be published as an RFC. [Clarification question] In Table 1 "Summary of recommendations", I wonder if the corresponding section numbers are correct. [Now] "SHOULD avoid using multiple ports" corresponds to Section 5.1 and "SHOULD use a randomized source port or equivalent technique" corresponds to Section 5.2 [New] "SHOULD avoid using multiple ports" corresponds to Section 5.1.1 and "SHOULD use a randomized source port or equivalent technique" corresponds to Section 5.1.2 I might be wrong, so please check. Also I have seen several typos (especially, missing parentheses around referenced section numbers) on this document, so please revise the texts before the publication of this document. Thank you. Take