Why does this list matter? Because it controls what domains you can use with wildcards in site to zone assignments within group policy.
If your domain is on the list - You can't use it with a wildcard.
You can see what the list is by using the following URL in IE8 or IE9:
res://urlmon.dll/ietldlist.xml
Looks like IE10 (and maybe 11) now uses:
ReplyDeletehttps://publicsuffix.org/
According to this blog post:
http://blogs.msdn.com/b/ieinternals/archive/2009/09/19/private-domain-names-and-public-suffixes-in-internet-explorer.aspx