For words that only have 3 letters, there isn't any 4th letter. One example is with the word “include”, there won't be any far more letters afterwards and so needs to be the word "include". The word “addict” is in the BIP39 wordlist however , you would've applied “addi” for https://captainbookmark.com/story19422757/the-5-second-trick-for-ledger-seed-phrase-bip39