Bip39 Binary Some words are shorter than four letters, such as the word “act”. Other words are for a longer time than four letters, for example “summary”. A person list of mnemonic can be utilized to produce several addresses. This method of building account was launched in BIP32 & BIP39 https://gogogobookmarks.com/story18622738/bip39-list-of-words-little-known-facts-about-bip39-word-list