DNS TXT field usage ?

Sun Mar 28 12:04:39 UTC 2010

Hello,

While watching some parked domains, I recently observed one which has a
TXT field containing some crypto value, something like a ssh key/RSA 512
or 1024 output (only the crypto part 'cvxvcvcxvcxv=' ).

For now, I have referenced the following usage of TXT
- DNS Server information/version
- SPF (format like "v=spf1 a mx -all") [1]
- DKIM (format like "k=rsa\; t=y\; p=MIGfMA0GCSqGSIb3 [...]
YA+OwSMWQIDAQAB", but always in _domainkey.<domain>) [2]
- not DNSSec as I supposed first (only DNSKEY, RR, RSIG, NSEC, not TXT)

Does someone know at what kind of usage this kind of value could
correspond ? (even if, nearly everything is possible)

Maybe somebody knows of a webpage referencing common usage of DNS fields ?
I found http://www.iana.org/assignments/dns-parameters but it points
only on RFC not practical usage.

Thanks a lot.
Best regards,

	Jul

[1] http://en.wikipedia.org/wiki/Sender_Policy_Framework
[2] http://www.ietf.org/rfc/rfc4871.txt (7.4)

Note: current RFC referencing TXT field is
http://www.ietf.org/rfc/rfc1035.txt
"TXT RRs are used to hold descriptive text."