Normally an OPORD is generated at the battalion, regimental, brigade, divisional, or corps headquarters and disseminated to its assigned or attached elements.
and adds additional details that pertain more to the minutiae of the actions a unit is tasked to conduct in support of the overarching operation.
He developed this as a standard format for himself and his subordinates while assigned to Fort Benning's Infantry School, Ranger & Tactics Department in 1957 to 1958.
An OPORD is formatted to organize an operation into five easily understood paragraphs: Situation, Mission, Execution, Sustainment (formerly Service and Support, currently referred to as Admin & Logistics by the US Marine Corps), and Command and Control.
The annexes and appendices allow the OPORD to be more easily read and understood by encouraging the inclusion or removal of material after its relevancy to the order's end user is determined.