GNOME has a few ways to type in characters that are not normally accessible via your keyboard.
By codepoint
- Hold down Ctrl + Shift
- Press U
- Type in the unicode code point
- Release Ctrl + Shift
- 3042: あ (hiragana ‘ah’)
- 00BD: ½
- 03A9: Ω
With compose key
Under the ‘Typing’ tab of Gnome Tweak Tool there is an option called ‘Position of Compose key’ I’ve set that to Alt Gr.
- Alt Gr + o + c: ©
- Alt Gr + ‘ + e: é