Bip39 Seed. Because the 24th is actually a checksum word, a list of 8 valid candidate words are calculated using the Python script 24thword.py. A copyright wallet passphrase is definitely an optional function that can be used in addition to your seed phrase to restrict use of your copyright wallet. https://morningdirectory.com/listings628000/bip39-words-https-linktr-ee-bip39-about-bip39