Bip39 recovery phrase https://685fcc02d9ea2.site123.me Though it works by using BIP32 system you could nevertheless import BIP39 seeds into Electrum wallet. Also aside from BIp32 There is certainly BIP44 Edition which some wallet use for your generation of seeds. For words that only have three letters, there isn't a 4th letter. https://unsplash.com/@morganvmyg