Bip39 Mnemonic Code Converter Tool. The passphrase is just not chosen within the predefined list of 2048 words – it could be any word or phrase you choose. BIP39 is usually a style and design implementation that lays out how copyright wallets make the set of words (or "mnemonic codes") https://tealbookmarks.com/story19154985/bip39-wallet-https-linktr-ee-bip39-a-review-of-bip39-generator