Bip39 blockchain http://www.video-bookmark.com/user/tucanewhmt The final action of BIP-39 is building the particular binary seed which can be then made use of as being a learn key in BIP-32 deterministic wallet or using other approaches. For words that only have three letters, there is not any 4th letter. For example While https://blogfreely.net/travenmdoq/create-your-own-distinct-bip39-mnemonic-expression-with-python-scripts