For words that have only 3 letters, there's no 4th letter. For example with the word “insert”, there aren't any additional letters Later on and so needs to be the word "include". The word “addict” is during the BIP39 wordlist however you might have employed “addi” for “addict”. By pursuing https://iwanttobookmark.com/story19136951/detailed-notes-on-copyright-wallet-seed-phrase-out-of-bip39