Bip39 Checksum. Entropy values needs to be sourced from a robust supply of randomness. This means flipping a good coin, rolling a good dice, sounds measurements etcetera. Usually do not use phrases from guides, lyrics from songs, your birthday or steet address, keyboard mashing, or something you think is random, https://directory-blu.com/listings556720/bip39-words-https-linktr-ee-bip39-rumored-buzz-on-bip39-standard