Bip39 docs https://www.4shared.com/s/fAf7kF4dLku Checksum development: A checksum is created from this entropy using SHA-256 hashing, which will help validate the mnemonic's integrity afterwards. For words that have only 3 letters, there's no 4th letter. As an example with the word “incorporate”, there are no much more letters Later on and https://health-lists.com/story21241711/bip39-seed-to-private-key-not-known-details-about-bip39-word-list-txt-https-x-com-tundra838554