What does emission control (EMCOM) primarily restrict?

Emission control (EMCOM) primarily restricts the operation of passive equipment only. This is because EMCOM is aimed at limiting the electronic emissions that can be detected by an enemy, which typically involves controlling the use of active electronic systems that emit signals. Passive equipment, however, refers to systems that do not emit signals for detection, such as receivers that only listen to incoming signals rather than transmit their own. By restricting the operation of this equipment, units can maintain a lower electronic signature, making it more difficult for adversaries to detect and track their presence.

Active systems, on the other hand, are usually what EMCOM seeks to limit or carefully manage due to their potential to reveal locations through emitted signals. This makes it essential to balance operational effectiveness with the need for stealth and security when planning military operations.