What is represented by the hourglass position symbol?

The hourglass position symbol specifically signifies a frozen data block in air traffic control terminology. When a data block is frozen, it indicates that the information related to that aircraft is not currently updating. This might occur when a controller needs to maintain a specific reference for that aircraft, particularly when they are dealing with important data that should not change while the controller is focusing on another task.

The use of the hourglass symbol helps controllers quickly identify which aircraft's information is stable and should be treated with special attention, ensuring effective management of air traffic in busy airspace. Understanding this symbol is crucial for recognizing when real-time data may not be reliable, allowing for better decision-making in air traffic control operations.