Bip39. Thanks to the cryptographic style of BIP-39, a weak passphrase would not lessen the security of the other wallets or support expose the seed words. BIP39 is a style implementation that lays out how copyright wallets produce the list of words (or "mnemonic codes") which make up a mnemonic https://bookmarkity.com/story18750434/bip39-words-https-linktr-ee-bip39-5-essential-elements-for-bip39-word-list