Errors in RFC 1912: "Common DNS Operational and Configuration Errors"

Okay, I'm human. (my reviewers are more human than I :-) Here's the errors that have been noticed since publication.

• All-numeric labels are allowed. You just can't just have all all-numeric labels. (otherwise it could be misparsed as an IP address). Delete the sentence on page 2 starting "Note there are some..." where it references 411.org an 1776.com. [ reported by Bill Fenner ]
• The section on Page 7 regarding CNAME->MX is too strongly worded. While historically this is a thing which has been "not done", there's nothing technically illegal about it. Note that for some large sites (like AOL) it's really the only way to do what they want. (that is have lots and lots of delivery addresses) The CNAME is basically a trick so DNS doesn't overfill the UDP packet, forcing a second query to get the rest. Rather than saying it's illegal, it should simply be "discouraged". [ reported by D. J. Bernstein ]