The menubar gives access to most AdiIRC features.
The menubar can be hidden by clicking Menubar -> View -> Menubar or by typing /menubar off.
When the menubar is hidden, the menubar menu can still be accessed by right-clicking the Titlebar-
It can also be shown at any time/anywhere by typing /showmenu -m, which can also be associated with a shortcut.
The /menubar command can be used to add/edit/remove any menu item. To have any changes persisent, put the commands in a on START script.