Anecdote time!

Some years ago I had a password on an account that contained a space character. One day, out of the blue, couldn’t log in. Went through the reset flow, picked another password that also happened to contain a space, still couldn’t log in.

I started poking at it and realized that I had to enter the space as `+` at the login form. It worked that way. I never quite figured out what they would’ve had to do to get the form encoding so specifically wrong.

Since then, I’ve tried to carefully consider just how “special” I want my special characters to be.