#NoTrayIcon
Disables the showing of a tray icon.
#NoTrayIcon
Specifying this anywhere in a script will prevent the showing of a tray icon for that script when it is launched (even if the script is compiled into an EXE).
If you use this for a script that has hotkeys, you might want to bind a hotkey to the ExitApp command. Otherwise, there will be no easy way to exit the program (without restarting the computer or killing the process). For example: #x::ExitApp.
The tray icon can be made to disappear or reappear at any time during the execution of the script by using the command Menu, Tray, Icon or Menu, Tray, NoIcon. The only drawback of using Menu, Tray, NoIcon at the very top of the script is that the tray icon might be briefly visible when the script is first launched. To avoid that, use #NoTrayIcon instead.
The built-in variable A_IconHidden contains 1 if the tray icon is currently hidden or 0 otherwise.
Related
Example
#NoTrayIcon