One basic method of signaling with a search line is this acronym.

• A. HALT
• B. SAFE
• C. OATH
• D. CALL

Answer: (C)

Signaling with a search line relies on quick, unambiguous cues that can be seen or felt even when visibility is poor. The four-part code in this context is OATH, a concise sequence that covers the essential exchange: O for On the line (or OK) to indicate the line is in place and movement can begin; A for Acknowledged to confirm the signal was received; T for Take up slack or Time to adjust tension and pace; H for Hold to stop movement or secure the line. This combination gives the team a simple way to start, confirm, pace, and stop without needing to shout, which is crucial in smoky or noisy conditions. It’s more flexible and informative than a single command like Halt or a general term like Safe or Call, which don’t convey a complete signaling routine.