A domain is typically of the form "www.MYDOMAIN.com", but you may also want to route all incoming requests for "MYDOMAIN.com" or "web.MYDOMAIN.com" to the same server. This is what we call a virtual domain. Different licenses allow different numbers of virtual domains.
You can use wildcards (* is the wildcard character) in virtual domains, but the wildcard MUST be the first character of the Virtual Domain. If you add a virtual domain called "*.mydomain.com", that will catch all domains that match that pattern.
