All necessary documentation sould be included in the script. More details may be included in here in the future. Until then, please see the project website at: http://www.stanback.net/code/godaddy-dyndns.html
pvormittag/php-godaddy-ddns
PHP class for updating A records on GoDaddy's DNS service. Includes an implementation of Dyn's DNS Update API for supporting record updates via various Dynamic DNS clients.
PHP