The precaution of prohibiting employees from bringing personal computing devices into a facility is what type of security control?

Physical controls involve tangible, physical mechanisms such as locks, mantraps, security guards, or device scanners that physically prevent access - a policy prohibition alone has no physical enforcement component.

Procedural controls, also called administrative controls, are policies, rules, and procedures that direct human behavior to reduce risk. A prohibition enforced through a workplace policy or employee agreement is procedural in nature - its effectiveness depends on compliance with a stated rule, not on a physical object or technical mechanism.

Technical controls rely on technology implementations such as network access control (NAC), endpoint management software, or port blockers to enforce restrictions - a verbal or written policy is not a technical control.

Compliance is not a recognized category of security control in standard frameworks such as NIST SP 800-53 or ISO 27001 - it describes adherence to controls, not a control type itself.