This has nothing to do with Linux. You can't type any of these at the Linux console.

For Windows users, I recommend WinCompose: https://github.com/samhocevar/wincompose

I use the Insert key, which would otherwise have no function.

I should use weird characters on my passwords. Especially weird characters that look like normal characters. Then I can learn off the compose key sequences and instead of a password manager I can write down all of the passwords on paper and laminate them and stick them to my monitor.

I will not actually do this

> ₫ "d-" DONG SIGN

Heh heh. He said "dong". Heh heh.

A couple more fun ones:

Compose: LLAP = "emoji doing the vulcan salute"

Compose: FU = "middle finger emoji"

Compose: <3 = ♥

You can also type music notes using Compose: # + QeEsf or #: ♩♪♫♬♮♯

Source: https://www.x.org/releases/current/doc/libX11/i18n/compose/e...

edit: minor formatting and describing emojis since they don't seem to be allowed

These work in both X and Wayland, even though they are an X feature. X/Wayland will consult the standard file, but will also consult a file ~/.XCompose. A number of people have created files with extended compose sequences, of which https://github.com/kragen/xcompose is possibly the best-known. If you install or change ~/.XCompose, you must restart your session (log out and back in again) for it to be recognized.

I used to bind the Compose key to Caps Lock, but I've recently decided that Right Alt is a better choice.

Another commenter mentioned WinCompose, which I have used very successfully with Windows 11. On a Mac, you might try https://github.com/Granitosaurus/macos-compose, which is quite usable, provided you install Karabiner Elements for the remapping.

I wish I could have a compose key on android