What is the term for a quick update to an operation order?

A fragmentary order is indeed the term used for a quick update to an operation order. It serves as a tool to modify existing orders or provide additional information without the need to issue a completely new order. Fragmentary orders are typically concise and focus on changes to elements such as timelines, tasks, or resource allocations based on updated information or situational developments.

This approach allows commanders to maintain operational flexibility and responsiveness in dynamic environments, ensuring that all personnel involved in the operation are informed about any changes that may impact their actions. In contrast, a warning order is generally issued to alert units of an upcoming operation, while an action order provides specific instructions to carry out missions and operational reports compile and communicate updates on unit activities and status, which are not necessarily quick adjustments to an existing order.