For words that have only 3 letters, there is not any 4th letter. One example is with the word “include”, there won't be any a lot more letters Later on and therefore has to be the word "include". The word “addict” is during the BIP39 wordlist however, you would have https://bookmarksea.com/story18882846/getting-my-bip39-words-to-numbers-to-work