If a TOP SECRET telephone calls a SECRET telephone, what is indicated on both devices?

When a TOP SECRET telephone calls a SECRET telephone, the classification level of the call will be displayed as SECRET on both devices. This is due to the classification system that governs secure communications. In this system, the highest classification is relevant for the purpose of communication security, but once a TOP SECRET device establishes a connection with a SECRET device, the calling device will adjust to the lower classification for the purpose of control of classified information.

This classification ensures that the communication adheres to the security protocols, preventing classified information from being shared at a higher level than the receiving device can process. Hence, while the origination may be at the TOP SECRET level, the interaction via the SECRET device causes both to indicate SECRET. Other choices do not accurately reflect this security procedure or the classification display requirements.