For words that only have 3 letters, there's no 4th letter. As an example with the word “include”, there are no far more letters afterwards and thus has to be the word "insert". The word “addict” is within the BIP39 wordlist but you would've utilised “addi” for “addict”. Obtaining a https://livebackpage.com/story4442197/a-review-of-bip39