File: //usr/share/webmin/virtual-server/help/matchall.html
<header>Website matches all sub-domains?</header>
When this option is enabled, requests for any URL under the domain (like
<tt>http://abc.example.com</tt>) will return the virtual server's website.
This can be useful if you host an application that can return different
content based on the requested domain name, such as Wordpress MU. <p>
If the virtual server's DNS domain is hosted on this system, Virtualmin
will also add the wildcard <tt>*</tt> DNS record when <b>Yes</b> is
selected. <p>
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