What does the TTY abbreviation "SK" indicate?

The abbreviation "SK" in TTY communication stands for "Stop Keying." This term is used to signal the end of a message, indicating that the sender has finished transmitting their information. In TTY or text telephony, it is crucial for users to communicate clearly, especially when using a medium that relies on typed messages rather than voice communication. Using "SK" helps prevent confusion and allows the receiving party to understand that they can now respond or that the conversation has concluded. This clarity is essential in emergency communication situations where precise understanding can be critical.