System-level shortcuts cannot be overridden
Aliases: reserved chords · system hotkeys · window-manager shortcuts
What it is
The operating system keeps a set of chords for window management and system services: application switching, showing the desktop, screenshot, force quit, input-method switch, moving a window to another display. Cannot be overridden means an app does not get to rebind those keys to its own commands. Winning that fight dismantles the desktop; it does not make the app faster.
Two commands inside an app that want the same chord can be handed to the user to rebind. System chords are not at that table.
Why it happens
Desktop usability is built on window operations that are the same in every application. People switch away, close, or send a window to the back with the same chord everywhere precisely because that chord belongs to no application. If the front app turns the same chord into “next tab” or “confirm dialog,” the window manager vanishes inside that app. People read it as the system breaking, because the failure sits on the application boundary: the keys are unchanged, the meaning flipped from “operating system” to “this window.”
The reserved table is maintained by the OS; the app process often never receives those events. Binding them produces a shortcut printed on a menu that cannot be pressed—or worse, one that can be stolen in some hosts and becomes a platform lottery. The desktop form factor treats window switching and multi-window arrangement as infrastructure, so ownership of this set is already settled at the form-factor layer. It is not a product choice.
Where it stops holding
Exclusive fullscreen games and slideshows sometimes eat almost every key; system chords are yielded for the exclusive period and must be returned the instant exclusivity ends. If the user rebinds reserved keys in system settings, avoiding the vendor’s default table can still collide—the user rewrote the desktop contract, and the app’s move is to mark “may be intercepted by the system.” Remote desktop and virtual machines stack two operating systems on one keyboard; colliding reserved tables are not a reason for an app to grab global hotkeys. Assistive-technology modifiers are another reserved table.
Applying it
- List the window-management and system-service chords of each target OS and keep default bindings off that list. Do not print a chord the system will eat.
- Do not register global hotkeys that steal application-switch, screenshot, or show-desktop while some other app is in front.
- Verify: with the app in front, press application-switch, force-quit, screenshot, show-desktop. Each should remain a system action. Then open the menu: any app command labeled with those chords is a bad binding.