This is an OPS-DIR review of Special Use Domain Name 'ipv4only.arpa' (draft-cheshire-sudn-ipv4only-dot-arpa-15)

This ID provides the special domain name “ipv4only.arpa” to be used by a client to discover the local network’s NAT64 prefix.

This document has been 4 years in the making and is now on its 15th version.  It has undergone a lot of revision since the first version.

The document is very clearly written, especially section 8, which is the meat of the document and could almost stand alone.  Unlike too many IETF documents, this one actually explains the “why” of the proposal – i.e., why was the decision made to do a feature in a particular way – this is great for learning and to make it less likely that implementors will try to “fix” something they do not understand.

imo - this document is ready to ship