Bip39 Checksum. While you will discover BIP39 wordlists in languages other than English, it's strongly not suggested to implement non-English words for wallet backups. It might make restoring the wallet tough or extremely hard. No, there isn't any technical Restrict to the length of the passphrase. On the other hand, https://ledbookmark.com/story5253852/bip39-word-list-https-linktr-ee-bip39-getting-my-ian-coleman-bip39-to-work