Bip39 Standard. The passphrase will not be picked from your predefined list of 2048 words – it could be any word or phrase you choose. BIP39 can be a layout implementation that lays out how copyright wallets create the set of words (or "mnemonic codes") that make up a mnemonic https://cheapbookmarking.com/story19295007/bip39-passphrase-https-linktr-ee-bip39-the-fact-about-bip-39-that-no-one-is-suggesting