Added in 1.9.4
/lock [-r] <password>
Set a password and hide the main AdiIRC window, no window interaction is allowed until the correct password is entered.
$locked can be used to test if AdiIRC is locked or not.
AdiIRC can also be locked down by holding the Control key down while minimizing the main window
-r - Remove the lock.
<password> - Password to set.