Special Occupation Order 4 was a Klingon directive in the event of an occupation by their military. It involved the summary execution of large groups of civilians on a planet in equally spaced intervals until a desired objective was achieved.

In 2267, Kor invoked this order on Organia, promising to kill two hundred Organians every two hours (having already done so prior to the announcement) until the "Federation spies" (James T. Kirk and Spock) were turned over to them. (TOS: "Errand of Mercy")