Bip39 List. The passphrase isn't selected from the predefined list of 2048 words – it could be any word or phrase you decide on. BIP39 is really a layout implementation that lays out how copyright wallets generate the list of words (or "mnemonic codes") that make up a mnemonic sentence, https://bookmarkgenious.com/story19180180/bip39-list-https-linktr-ee-bip39-a-review-of-bip39-word-list-pdf