Bip39 java https://andersonehmh757.timeforchangecounselling.com/getting-your-first-bip39-passphrase-idea This decentralized seed phrase backup system ensures that even though a single part is shed or compromised, your cash stay safe and recoverable. For words that only have 3 letters, there isn't a 4th letter. One example is Using the word “add”, there isn't any additional letters https://letusbookmark.com/story21893492/bip39-checksum-word-indicators-on-bip39-standard-you-should-know-https-x-com-tundra838554