Bip39 Ozon. Although it uses BIP32 approach you'll be able to even now import BIP39 seeds into Electrum wallet. Also besides BIp32 There may be BIP44 Variation which some wallet use with the era of seeds. Seed phrases are very important for accessing private keys, which might be complex strings https://socialbaskets.com/story4163084/bip39-browser-not-known-factual-statements-about-bip-39