https://www.crockford.com/base32.html https://www.crockford.com/base32.html > We chose a symbol set of 10 digits and 22 letters. We exclude 4 of the 26 letters

https://www.crockford.com/base32.html https://www.crockford.com/base32.html > We chose a symbol set of 10 digits and 22 letters. We exclude 4 of the 26 letters: I L O U. I had never heard of Base32 Crockford before. The whole rationale is clever.