If Khaled wanted everyone to know about the /registration command, it would be documented.
There's a greater chance that such a command exists because the Help > Register menu item disappears after you register, leaving no means for someone to 'correct' their information when they decide to become legit.
One should only have to give this command out to users who have previously cracked mIRC. To say the least, we shouldn't be giving it out.
- Raccoon
