Contents| help.ubuntu.com
Remember, how Shift key works? Shift is called the second level input modifier key. Just like that, on Linux there are 3-d and 4-th level input chooser keys you can hold down to type special text symbols from your keyboard.| fsymbols.com
Find out how to setup and use Compose Key shortcuts on Linux. Contains a list of Compose Key sequences. Type text symbols with your keyboard.| fsymbols.com