Bip39 Seed. At first you'll want to retail outlet it SEPARATELY from the seed. Getting your seed and your passphrase in the exact same location defeats the objective of getting a passphrase in the first place. BIP39 specifies a list of 2048 words from which the mnemonic phrase is picked. https://minibookmarking.com/story19233956/bip39-https-linktr-ee-bip39-the-2-minute-rule-for-bip39-word-list