For words that have only three letters, there's no 4th letter. As an example with the word “insert”, there won't be any more letters afterwards and thus must be the word "include". The word “addict” is within the BIP39 wordlist but you would've utilised “addi” for “addict”. BIP39 and forty https://networkbookmarks.com/story18993247/the-invalid-bip39-phrase-diaries