It's to do dynamic updates on a system that doesn't have a restful api.
There is a linux script which i've been looking at and what they do is generate the correct string and use netcat to send the update.
The netcat is performed as follows
echo -n $string|cut -d ' ' -f 1`"|netcat -c -w 1 -u "server.fqdn" portnumber
if i could get some way of recreating this it could be a script that could be useful to the community intersted in IPv6 for using SixXS. I've also emailed the SixXS team to find out if they have any plans for a restful API as this would be very useful.