A panel ______ detail is specifically associated with HVAC control systems. What is the missing word?

The term "Terminal" is the correct choice as it directly refers to the component in HVAC control systems where connections are made for control signals and power. Terminal details in electrical prints are essential for showing how various heating, ventilation, and air conditioning components interface and communicate with one another. This includes connections to sensors, actuators, and control panels, which are crucial for the functioning and efficiency of HVAC systems.

Understanding this term is necessary for interpreting electrical diagrams, as it helps in identifying where connections occur and how multiple systems integrate. Other options such as "Enclosure," "System," and "Panel," while related to electrical work, do not specifically highlight the connections and details crucial for HVAC controls like "Terminal" does. Each of these alternatives conveys a broader concept that is not directly associated with the specific connections involved in HVAC control systems.