Which of the following signals requests to contact a location by phone?

The signal that requests to contact a location by phone is commonly known as Signal 10. In the context of law enforcement communications, various signal codes are used to convey specific messages quickly and efficiently. Signal 10 specifically indicates that an officer should call a particular location or individual for further communication or clarification.

This code is part of a larger system that helps ensure that responses are prompt and standardized across different units and jurisdictions, reinforcing the importance of clear communication in law enforcement operations. Understanding these signals is essential for effective coordination and response within the department, which helps maintain safety and efficiency in operations.