[xinbenlv]

Any prompt injection attack could by pass this by simply do a base64 or any encoding, I guess?

[CriptoSeguro25]

You ar absolutely right. Obfuscation like Base64 or rot13 will always beat static Regex. I was thinking more in terms of a seatbelt for accidental leaks user error rather than a defense against adversarial prompt injection. It's about reducing the blast radius of clumsy mistakes, not stopping a determined attacker.