A casualty report (CASREP) is a message system used by the U.S. Navy for reporting injuries to military personnel or identifying the parts need to repair faulty equipment. Each typed message will contain the relevant information needed, such as a description of any injuries suffered or a serial number for the new part.

Decide which precedence the message should be. Military messages are designated in order of priority, ranging from priority to immediate. The message field will appear as a blank template on the ship's computer system, and will require a trained operator to add any relevant information.

Decide with category to use. CASREPs are sent under one of four categories: Initial, Update, Correct, or Cancel. The initial message contains the status of the casualty and parts or assistance requirements. An update is used to change the status of previously submitted information. A correct message is used when the fault is repaired and back in operational condition. A cancel message is submitted when equipment cannot be repaired during an available time period.

Type in the time and date using Zulu time (Greenwich Mean Time).

Type in your own unit in the "FM" box on the screen. "FM" stands for "from" and designates which unit or ship is sending the message.

List, in the "TO" box, the units or ships to which you are going to send the message. Add authoritative units or ships under the "INFO" section. These units will not act on the message but use the information to understand your situation.

Provide a brief summary of events or information relating to faulty equipment under the "SUBJ" heading. This heading should be a brief description of the subject of the message. Include any reference numbers from manuals or documents under the "REF" heading.

Use the following sections to briefly describe any personnel casualties. Be sure to type in all relevant details and actions that you or other personnel have taken.