Bip39 Vs Slip39. The passphrase is just not picked from the predefined list of 2048 words – it can be any word or phrase you end up picking. Mnemonics are representation of entropy. Initial step entails making a call regarding the amount of entropy you consider Harmless on your operations. https://thebookmarkage.com/story18641937/bip-39-https-linktr-ee-bip39-helping-the-others-realize-the-advantages-of-bip39