Bip39 Passphrase. Now, at the next degree we use these receiving and change essential bunch to deliver person personal keys. Use the above mentioned make private keys and chain code and move them to the above mentioned stated purpose kchild = kpar + hash(Kpar, cpar, i) to create specific keys. https://onelifesocial.com/story4370454/bip39-mnemonic-https-linktr-ee-bip39-a-review-of-bip39-words