Bip39 regex https://www.demilked.com/author/gobnettlmz/ Even though it makes use of BIP32 approach it is possible to nevertheless import BIP39 seeds into Electrum wallet. Also in addition to BIp32 There exists BIP44 Edition which some wallet use for the technology of seeds. For words that only have 3 letters, there's no 4th https://atozbookmarkc.com/story20381845/bip39-vs-the-fact-about-bip39-word-list-github-that-no-one-is-suggesting-https-linktr-ee-bip39