Bip39 light standard https://franciscougju442.bravesites.com/entries/general/Produce-Bitcoin-Addresses-from-Seed-Every-Little-Thing-You-Required-to-Know BIP85: A more recent proposal enabling the deterministic derivation of multiple BIP39 mnemonic seeds from the learn seed. For words that only have three letters, there isn't any 4th letter. For instance With all the word “incorporate”... https://bookmarklinkz.com/story19789331/bip39-word-generator-how-bip39-wallet-can-save-you-time-stress-and-money-https-x-com-tundra838554