Bip39 mnemonic example https://ameblo.jp/generate-bip39brooks/entry-12913353546.html Even though it employs BIP32 system you could still import BIP39 seeds into Electrum wallet. Also other than BIp32 There may be BIP44 Edition which some wallet use with the technology of seeds. Not like standard wallets derived only from a seed phrase, passphrase-secured wallets are https://bookmarknap.com/story11288048/dbs-money-value-a-simple-key-for-bip39-github-unveiled-https-linktr-ee-bip39