Iframed and embedded players
For iframed or embedded players, the website considered will be the source website.
Localhost (127.0.0.1) is always whitelisted. This means that you do not have to configure anything to perform tests locally.
"www" subdomain is transparent to the whitelisting, meaning that "mywebsite.com" is equivalent to "www.mywebsite.com" and vice-versa.