Bip39 release date https://bip39marco.mystrikingly.com/ Even though it uses BIP32 system you'll be able to still import BIP39 seeds into Electrum wallet. Also besides BIp32 You can find BIP44 Edition which some wallet use for the era of seeds. For words that have only three letters, there's no 4th letter. For https://bookmarkstime.com/story21220570/bip39-word-list-bip39-generator-secrets-https-t-me-bip39-chat