How is the coded reply from a friendly craft displayed on the PPI scope?

The coded reply from a friendly craft is displayed on the Plan Position Indicator (PPI) scope as a dashed line. This representation is important because it allows for a clear distinction between different types of returns on the radar display. The dashed line specifically indicates that the return is coming from a friendly source as opposed to an unknown or hostile target, making it easier for the operator to identify and track friendly craft amidst other radar returns.

This visual differentiation is crucial for situational awareness in operations involving multiple aircraft and vessels, as it helps to prevent misinterpretations that could lead to friendly fire incidents. By using a dashed line, operators can quickly assess the radar display and make informed decisions based on the information presented.