Bip39 passphrase https://atavi.com/share/xbwf7vz16jgof Even though it utilizes BIP32 approach it is possible to continue to import BIP39 seeds into Electrum wallet. Also aside from BIp32 there is BIP44 version which some wallet use for the era of seeds. BIP39 simplifies key management by changing prolonged cryptographic info with simple-to-use words. https://dmozbookmark.com/story20021909/bip39-min-js-about-bip39-2048-words-https-x-com-tundra838554