What does the Signals code refer to?

• A. System of verbal communication using the letters of the alphabet only
• B. System of communication that combines numbers and letters of the alphabet, or the combination of some or all of the above to transmit messages
• C. System of communication using numbers followed by the word signal
• D. System of communication by which 10 precedes numbers that stand for specific activities

Answer: (C)

Signals code is a system that uses numbers followed by the word signal to convey instructions. This format lets responders quickly and unambiguously communicate actions or statuses, because each number points to a predefined meaning in the codebook. It’s different from alphabet-only verbal systems, which rely on letters and spoken words, and from mixed alphanumeric schemes that don’t stick to the strict numeric-then-signal pattern. The rule about numbers preceding signal is the core structure of this coding approach, aligning messages with a standardized, easily interpretable format in safety communication.