Bip39 Checksum. At the start you should retail store it SEPARATELY from the seed. Possessing your seed plus your passphrase in a similar spot defeats the objective of having a passphrase to start with. None of such examples are concerned with arguments that you'd use for differing types of typos, https://ztndz.com/story23511903/bip39-mnemonic-https-linktr-ee-bip39-the-best-side-of-bip39