What is the indication by the relieving specialist that the verbal briefing can start?

The indication by the relieving specialist that the verbal briefing can start is appropriately given by the term "Preview." This term suggests the intention to outline or summarize the key points of the briefing that will follow, effectively preparing participants for the details that will be shared. A "Preview" typically serves to set the stage for the communication that is about to occur, ensuring everyone is oriented and can engage with the information in a structured manner.

While other terms like "Begin Briefing" or "Initiate Discussion" might imply a start to the verbal exchange, they do not specifically denote the preparatory context that a "Preview" conveys. "Start Communication" also lacks the specific focus on summarizing or outlining that precedes a detailed briefing. Thus, "Preview" is the most precise term to indicate the beginning of a structured verbal briefing.