For words that have only 3 letters, there is no 4th letter. One example is with the word “include”, there are no a lot more letters Later on and therefore needs to be the word "incorporate". The word “addict” is while in the BIP39 wordlist however, you might have utilised https://baidubookmark.com/story18819806/not-known-facts-about-bip39-english-words