Bip39 Usdt Some words are shorter than four letters, including the word “act”. Other words are for a longer time than four letters, like “abstract”. A single list of mnemonic may be used to produce several addresses. This method of building account was launched in BIP32 & BIP39 long time https://advicebookmarks.com/story26260537/bip39-standalone-considerations-to-know-about-seed-phrase-generator