Which is not an operational category for an intrusion detection system?

An intrusion detection system (IDS) is designed to monitor and analyze network traffic or physical systems for signs of unauthorized access or attacks. The operational categories typically refer to environments in which these systems are employed and how they function within those contexts.

Commercial security systems, residential security systems, and hybrid security systems all represent environments or methods of deployment for IDS. Commercial security systems are used in business settings to protect sensitive company data and assets. Residential security systems are designed for home protection, focusing on monitoring break-ins and ensuring personal safety. Hybrid security systems combine elements from both commercial and residential environments, making them versatile for various applications.

On the other hand, a proprietary alarm system refers to a specific type of security technology that is custom-built or tailored for a unique requirement, rather than a standard operational category. While proprietary alarm systems can contribute to security, they do not fit within the broader context of operational categories used to classify how intrusion detection systems are implemented across different environments. Hence, this distinction clarifies why this option stands apart from the recognized operational categories for intrusion detection systems.