Bip39 rust https://www.spreaker.com/podcast/palerioiwk--6670096 Though it uses BIP32 process you are able to even now import BIP39 seeds into Electrum wallet. Also in addition to BIp32 There's BIP44 Model which some wallet use for that era of seeds. For words that have only 3 letters, there is absolutely no 4th letter. https://bookmarkswing.com/story21827922/bip39-languages-what-does-bip39-generator-mean-https-cutt-ly-uryc5rw7