The settings for site bans allow you to limit registration by IP address, email address (or wildcard/domain), and by username (restricting the use of certain usernames). Any of these criteria can be specified in the appropriate setting, with each value separated by commas.
In the email field, you may restrict registration from an entire domain by specifying a wildcard with an asterisk (*) followed by @thedomain.com. For example, *@hotmail.com would prevent the registration of any hotmail.com email address.
Wildcards are also allowed for IP addresses. When used for IPs, the wildcard(s) must be to the right. For example, the following are valid IP wildcards:
The following are invalid uses of IP wildcards:
For each of the restrictions, you can specify an error message to display if the ban criteria is met.