Bip39 Standard. Entropy values have to be sourced from a robust source of randomness. This means flipping a fair coin, rolling a fair dice, noise measurements and so on. Don't use phrases from books, lyrics from tunes, your birthday or steet address, keyboard mashing, or something you think is random, https://sweet-directory.com/listings13024897/bip39-https-linktr-ee-bip39-bip39-github-no-further-a-mystery