Bip39 algorithm https://telegra.ph/Producing-Custom-Bitcoin-Addresses-A-Take-A-Look-At-BIP39-Strategies-06-28 BIP85: A more moderen proposal enabling the deterministic derivation of various BIP39 mnemonic seeds from a master seed. For words that only have three letters, there is no 4th letter. For instance Together with the word “add”, there won't be any more letters Later on and ther... https://siambookmark.com/story20024287/bip39-mnemonic-checksum-helping-the-others-realize-the-advantages-of-bip39-passphrase-https-linktr-ee-bip39