By that you mean I can specify not only domains but also subdomains?
One of my entries currently looks like this:
whiteListIframe(/^(https?:)?\/\/books.google\.(gr|pt|ae|au|com|de|fr|se|ca|co.uk|es|dk|co.za|fi|cz|be|nl|at|cn|com.br|jp|it|is|in|ie|id|mx|tr)\/.+&output=embed.*/i);
But I guess it’s possible to achieve this “the long way” without regex, at least if we drop the embed part…