Alt Graph Key

By Xah Lee. Date: 2023-03-22.

Sun Microsystems Type 6 keyboard meta — The `Meta`, `Compose`, `AltGraph` keys, on Sun Microsystem Type 6 Keyboard

The Alt Graph key, usually labeled “AltGr”. This key is a modifier key. It is for inserting special characters. Press AltGraph+key to insert a special char.

For example, when using US international layout:

AltGraph+e inserts é
AltGraph+c inserts ©

This key is on some European keyboards. It's also on Sun Microsystem Type 6 Keyboard .

Which character is inserted with what key is dependent on the keyboard layout.

On Microsoft Windows, the right Alt becomes AltGraph if you set your keyboard layout to one of European language layouts. 〔see International Keyboard Layouts〕
On macOS, the ⌥ option is the AltGraph.

Mac Keyboard Viewer

The first key of similar idea, seems to be the The Top Key of the Stanford AI Lab (SAIL) keyboard

Alt Graph Key, Compose Key, Dead Key

Alt Graph Key, Compose Key, Dead Key
Alt Graph Key
Compose Key
Dead Key