Bip39 Passphrase Generator. If you would like to refresh your memory about the fundamentals of how copyright wallet seed phrases and passphrases perform, look at reviewing the Vault12 report in regards to the BIP39 standard. For words that have only 3 letters, there is absolutely no 4th letter. For instance https://thedirectoryblog.com/listings13115992/bip39-github-https-linktr-ee-bip39-the-greatest-guide-to-bip39-checksum