What element is not required on a security officer’s advertisements?

In the context of security officer advertisements, the omission of a license number is justified because licensing requirements can vary significantly depending on the jurisdiction and the specific type of services offered. While it is essential for security officers to be licensed to operate legally, the details about this licensing do not need to be explicitly included in public advertisements.

Instead, advertisements typically emphasize the services provided and the officer's contact number to attract potential clients and facilitate communication. Investment promotions, while potentially relevant for marketing, are not a standard requirement and can differ based on the nature of the services offered. Therefore, including the license number is not a mandated aspect of advertisement for security officers, making it the element that is not required.