Bip39 Mnemonic. As palavras desta frase são selecionadas de uma lista definida de 2048 palavras, que pode ser acessada aqui ou listada abaixo: For words that only have three letters, there is absolutely no 4th letter. For instance Along with the word “insert”, there aren't any extra letters Later on https://phase2directory.com/listings13051961/bip39-tool-https-linktr-ee-bip39-facts-about-bip39-checksum-revealed