Bip39 Standard. Since the 24th can be a checksum word, a list of eight valid prospect words are calculated using the Python script 24thword.py. Based on your personal scenario, it is possible to decide that for yourself, however you can see why lots of authorities advocate against placing a passphrase. https://ezylinkdirectory.com/listings13050523/bip39-passphrase-https-linktr-ee-bip39-not-known-facts-about-bip39-mnemonic-generator