Bip39 Light Standard. Regardless that it makes use of BIP32 approach you'll be able to still import BIP39 seeds into Electrum wallet. Also in addition to BIp32 You can find BIP44 version which some wallet use for that era of seeds. We welcome contributions from the Group to create Seed https://financemanager37148.wikiexcerpt.com/3259698/the_anatomy_of_a_bip39_phrase_entropy_words_and_stability