Bip39 rules https://www.demilked.com/author/gobnettlmz/ BIP85: A newer proposal letting the deterministic derivation of a number of BIP39 mnemonic seeds from the learn seed. For words that only have three letters, there isn't a 4th letter. Such as With all the word “increase”, there isn't any a lot more letters Later on https://bookmarkingace.com/story20175316/bip39-cryptotag-new-step-by-step-map-for-bip39-word-list-txt-https-t-me-bip39-chat