For words that only have 3 letters, there isn't any 4th letter. For instance with the word “include”, there are no extra letters afterwards and thus needs to be the word "incorporate". The word “addict” is in the BIP39 wordlist however, you would've utilised “addi” for “addict”. Art is usually https://bookmarkplaces.com/story18747642/helping-the-others-realize-the-advantages-of-bip39-mnemonic-phrase-tool