Bip39 test vectors http://www.mediafire.com/file/uilrjfajg2ami24/pdf-14673-57158.pdf While it takes advantage of BIP32 technique you could even now import BIP39 seeds into Electrum wallet. Also other than BIp32 There's BIP44 version which some wallet use to the technology of seeds. Just how much security does a passphrase increase? A BIP39 passphrase noticeably improves https://nybookmark.com/story21822476/bip39-mnemonic-generator-5-tips-about-bip39-checksum-you-can-use-today-https-linktr-ee-bip39