RFC 4034, "Resource Records for the DNS Security Extensions", March 2005Source of RFC: dnsext (int)
Errata ID: 1062
Reported By: Peter Koch
Date Reported: 2005-09-13
Verifier Name: Brian Haberman
Date Verified: 2012-05-01
Section 6.2 says:
3. if the type of the RR is NS, MD, MF, CNAME, SOA, MB, MG, MR, PTR, HINFO, MINFO, MX, HINFO, RP, AFSDB, RT, SIG, PX, NXT, NAPTR, KX, SRV, DNAME, A6, RRSIG, or NSEC, all uppercase US-ASCII letters in the DNS names contained within the RDATA are replaced by the corresponding lowercase US-ASCII letters;
It should say:
Compare with RFC 3597 (section 7):
"As a courtesy to implementors, it is hereby noted that the complete
set of such previously published RR types that contain embedded
domain names, and whose DNSSEC canonical form therefore involves
downcasing according to the DNS rules for character comparisons,
consists of the RR types NS, MD, MF, CNAME, SOA, MB, MG, MR, PTR,
HINFO, MINFO, MX, HINFO, RP, AFSDB, RT, SIG, PX, NXT, NAPTR, KX, SRV,
DNAME, and A6."
Almost exactly the same list. One HINFO too much is no issue,
but if this actually should be TXT it's a real typo.
neither TXT nor HINFO contain domain names in RDATA, so it's a bug in both
RFC 3597 and 4034, although one that doesn't hurt. One could also argue that the list lacks NSAP-PTR, but then that's as obsolete as MD ans MF.