If you're using a 60% keyboard, or any other layout with no F-row, you will have noticed that there is no dedicated Escape key. Grave Escape is a feature that allows you to share the grave key (<code>`</code> and `~`) with Escape.
Replace the `KC_GRV` key in your keymap (usually to the left of the `1` key) with `KC_GESC`. Most of the time this key will output `KC_ESC` when pressed. However, when Shift or GUI are held down it will output `KC_GRV` instead.
If Mary presses GESC on her keyboard, the OS will see an KC_ESC character. Now if Mary holds Shift down and presses GESC it will output `~`, or a shifted backtick. Now if she holds GUI/CMD/WIN, it will output a simple <code>`</code> character.
On macOS, Command+<code>`</code> is by default mapped to "Move focus to next window" so it will not output a backtick. Additionally, Terminal always recognises this shortcut to cycle between windows, even if the shortcut is changed in the Keyboard preferences.
There are several possible key combinations this will break, among them Control+Shift+Escape on Windows and Command+Option+Escape on macOS. To work around this, you can `#define` these options in your `config.h`:
