Per,
The whole purpose with the DYNDns status link is in case there is some kind of error. If you see:
"DynDns status OK"
then the info you get by clicking the link most likely shows the expected valid reply from the DYNDns system.
So you really don't need to know something about the "programming details" in that status, just be able to retrieve it and give it to us in case there is something wrong.
The status messages "DynDns status Unknown" or ""DynDns status Error" would have made the status link info "interesting"
As for what to look for in that message: It is several pieces of that message which need to be valid and present for the DynDNS status to be considered ok.