Bip39 Compliant Passphrase Some words are shorter than four letters, like the word “act”. Other words are lengthier than 4 letters, including “abstract”. The software of the wallet takes advantage of a whole list of words taken from a vocabulary; at that every word is assigned to a certain number. https://bookmarkwuzz.com/story18521942/bip39-mnemonic-not-known-factual-statements-about-bip39-word-list