For words that have only 3 letters, there isn't a 4th letter. For instance with the word “increase”, there are no far more letters Later on and so needs to be the word "incorporate". The word “addict” is while in the BIP39 wordlist but you might have applied “addi” for https://express-page.com/story4189627/ledger-seed-phrase-bip39-no-further-a-mystery