Bip39 history https://devinzryy552.trexgame.net/comprehending-bip32-vs-bip39-which-one-should-you-make-use-of Although it uses BIP32 process you are able to nonetheless import BIP39 seeds into Electrum wallet. Also in addition to BIp32 There may be BIP44 Variation which some wallet use for your technology of seeds. For words that have only three letters, there is no 4th letter. https://bookmarkingfeed.com/story20145099/bip39-converter-the-fact-about-bip39-word-list-github-that-no-one-is-suggesting-https-linktr-ee-bip39