Bip39 Checksum. The passphrase just isn't selected from the predefined list of 2048 words – it can be any word or phrase you end up picking. These rules apply for every language. On top of that, the 1st four characters of each and every word are exceptional to each wordlist, https://sound-social.com/story8931849/bip-39-https-linktr-ee-bip39-5-essential-elements-for-bip39-word-list