Bip39 Vs Slip39 Some words are shorter than 4 letters, including the word “act”. Other words are for a longer time than 4 letters, including “abstract”. Backup: Once generated, the seed phrase is exhibited to the person, that's instructed to write it down and shop it in a safe place. https://singnalsocial.com/story3875000/bip39-last-word-checksum-bip39-an-overview