What specific type of cryptographic material or secret should *neverbe present in client-facing OTP integration documentation, even in redacted or example forms?

The specific type of cryptographic material or secret that should never be present in client-facing One-Time Password (OTP) integration documentation, even in redacted or example forms, is the cryptographic shared secret key. This key, also commonly referred to as the seed or master key, is a unique, high-entropy, randomly generated sequence of bytes or characters that forms the core of an OTP system's security, especially for algorithms like HMAC-based One-Time Passwords (HOTP) and Time-based One-Time Passwords (TOTP). An OTP is a temporary password valid for a single use, designed to enhance security. In the context of H....