In extremely time-sensitive situations, what may be the only message provided?

In extremely time-sensitive situations, the most appropriate form of communication is an EXORD, or Execute Order. An EXORD is specifically designed to direct forces to take action in a rapid manner, thus it serves as a crucial tool for commanders needing to convey immediate instructions.

The EXORD typically follows the receipt of previous orders and is issued to initiate immediate operations, ensuring that all units understand the urgency and can act accordingly without delay. Its nature is to expedite execution, making it vital in high-pressure scenarios where time is of the essence.

Other orders like OPORD (Operations Order), WARNORD (Warning Order), and FRAGO (Fragmentary Order) serve important functions but may not always convey the immediacy required. An OPORD provides detailed planning information for an operation, while a WARNORD alerts units of an impending operation, and a FRAGO modifies an existing OPORD. These are useful in various contexts but do not fulfill the same urgency as an EXORD in critical conditions.