"发号施令" is a four-character idiom, or chengyu, formed through a parallel and reinforcing structure common in classical Chinese. It combines two nearly synonymous verb-object pairs: "发号" (fā hào, "to issue commands", literally "issue numbers/signals") and "施令" (shī lìng, "to give orders", literally "implement orders"). The two halves are stacked together in a coordinated, parallel manner to create a compound meaning that is more emphatic and rhythmically complete than either part alone. This structure intensifies the sense of authoritative command, historically rooted in military contexts where signals (号) and orders (令) were proclaimed, and now figuratively describes anyone who issues directives in an authoritative, often domineering, manner.