Bip39 github https://www.sbnation.com/users/typhanhmdy BIP85: A more recent proposal allowing the deterministic derivation of numerous BIP39 mnemonic seeds from the master seed. For words that have only 3 letters, there is absolutely no 4th letter. As an example With all the word “increase”, there isn't any a lot more letters afterwards https://www.symbaloo.com/mix/bookmarks-xfkm