Bip-39 https://gravatar.com/sparklyusually6089a4f337 D'CENT Biometric Wallet - A hardware wallet which has a biometric authentication feature, supporting BIP39 seed phrases and delivering an additional layer of security. For words that have only 3 letters, there's no 4th letter. One example is Using the word “add”, there isn't any more letters Later https://natural-bookmark.com/story20468530/bip39-word-list-trust-wallet-the-smart-trick-of-bip39-word-list-github-that-no-one-is-discussing-https-linktr-ee-bip39