Bip39 words http://www.mediafire.com/file/uilrjfajg2ami24/pdf-14673-57158.pdf BIP85: A more moderen proposal enabling the deterministic derivation of many BIP39 mnemonic seeds from the grasp seed. For words that only have 3 letters, there isn't a 4th letter. Such as with the word “add”, there won't be any much more letters Later on and so https://artybookmarks.com/story20226576/bip39-release-date-5-tips-about-bip39-checksum-you-can-use-today-https-cutt-ly-uryc5rw7