Bip39 reddit https://edgargvkh682.theburnward.com/a-novice-s-overview-to-getting-a-bip39-mnemonic-expression Regardless that it employs BIP32 method you are able to still import BIP39 seeds into Electrum wallet. Also aside from BIp32 There exists BIP44 Model which some wallet use to the era of seeds. For words that have only three letters, there isn't any 4th letter. As https://opensocialfactory.com/story22101439/bip39-tool-bip39-github-an-overview-https-cutt-ly-uryc5rw7