Bip39 Ian Coleman. The passphrase isn't selected from your predefined list of 2048 words – it may be any word or phrase you select. BIP39 is really a design implementation that lays out how copyright wallets make the set of words (or "mnemonic codes") which make up a mnemonic sentence, https://bookmarkshq.com/story20372262/bip39-wallets-https-linktr-ee-bip39-the-basic-principles-of-bip39-mnemonic