Apache Reference: mod_proxy, ProxyDomain
Default Intranet Domain Name
Syntax: ProxyDomain A
Example: ProxyDomain .mycompany.com
Since: Apache 1.3
This directive is useful only for Apache proxy servers that reside within
intranets. It specifies the default domain name (domain-name) to which
the Apache proxy server will belong. If a proxy request to a host
without a domain name is encountered, the directive will generate
a redirection response to the same host with the configured domain-name
appended.