What is usually indicated by codes such as "10-1" and "10-2"?

Codes like "10-1" and "10-2" typically fall under the category of indicating how a transmission is being received. Specifically, "10-1" often means that a transmission is unreadable or barely audible, while "10-2" signifies that the transmission is being received clearly. These codes are part of a standardized set often used in law enforcement communications to ensure clarity and efficiency among officers in the field. Understanding these codes allows officers to quickly assess communication quality, making it easier to react and respond appropriately during operations.

In contrast, the other options focus on different contexts of law enforcement communication. Reports of illegal activity would not specifically be communicated through transmission quality codes, officer locations are usually denoted by separate identifiers or dispatch protocols, and time-sensitive emergencies are often conveyed using distinct codes that indicate urgency rather than the clarity of communication.