ken_b - 12:16 am on Oct 17, 2012 (gmt 0)

My understanding is that

example.com
disavows all links from that domain.

www.example.com
is a different domain and needs it's own disavowal.

subdomain.example.com
disavows all links from that subdomain

example.com/somefile.htm
disavows links from that specific page.