For words that only have 3 letters, there is no 4th letter. For instance with the word “include”, there isn't any more letters afterwards and so must be the word "insert". The word “addict” is during the BIP39 wordlist however , you would have used “addi” for “addict”. Unlock your https://rotatesites.com/story21010309/top-guidelines-of-bip39-word-list-pdf