Forums Feature Suggestions vhost - possible to detect if using one?

It is possible, and can already be done using scripting methods, conditionally that the person/bot running the code has sufficient access to be able to determine the difference.

I know I can do this on the network where I have IRCops status, but I also know that if I was to disable my IRCops status, then I wouldn't be able to determine the difference.

Additionally, this may be (and I suspect would be) different depending on the network and/or IRCd.

Normally only IRCops (or higher) can see your actual host configuration when a virtual host is used.