Radio silence
Radio silence, or subspace silence, was an operating protocol for starships that were either in combat or operating in a combat zone. When radio silence was invoked, the ship sent absolutely no outgoing communications – not even to acknowledge incoming transmissions.

In 1986, while on a mission to obtain humpback whales to save Earth of the future, James T. Kirk had his crew divided into three teams. The teams were given their assignments and each individual was given a phaser and a communicator. Kirk instructed his crew that, save for emergencies, that they were to maintain radio silence. ()

In 2155, Hoshi Sato refused to break radio silence by allowing Nathan Samuels to contact Admiral Gardner. ()

In 2267, after Spock had commandeered the  with forged Starfleet orders, he ordered Lieutenant Nyota Uhura to maintain radio silence, when the ship was hailed by Starbase 11. ()

Radio silence was used by the  and the Romulan Bird-of-Prey during the battle in the Romulan Neutral Zone. ()

In 2268, when the Enterprise received a Priority 1 distress call, subspace silence was maintained until the ship reached Deep Space Station K-7, upon which James T. Kirk, seeing that all was apparently peaceful, broke silence to ask the nature of the emergency. ()

After Admiral Kirk stole the Enterprise in order to return Doctor McCoy to the Genesis planet in 2285, Starfleet attempted to contact Captain J.T. Esteban to warn him of the Enterprises approach. Kirk found it unusual that Esteban did not respond, and wondered Esteban's intentions aloud before he eventually decided to break radio silence and radioed ahead so as to "send Captain Esteban my compliments." ()

In 2366, a replica of Captain Jean-Luc Picard enforced a form of radio silence on the , belaying an order from Commander William T. Riker to contact the  to inform them of a change of orders, as doing so would have revealed that these orders were fictional. He then stated that there would be no further communication off the ship without his prior authorization. ()

In 2368, when the long-term memories of the crew of the Enterprise-D were temporarily erased by the impostor Kieran MacDuff, the false orders from Starfleet placed in the ship's computer stated that they were to maintain radio silence. This was part of the ruse, as any contact with Starfleet would have revealed that the supposed orders to destroy the Lysian Central Command were false. ()

In 2372, Michael Eddington told  to maintain radio silence so the theft of the Class 4 industrial replicators would not be discovered. ()

While it was stranded behind enemy lines in early 2374, the  observed strict radio silence to avoid detection by the Jem'Hadar. This had the unfortunate side effect of leaving Starfleet Command unaware of the fact that the Valiant was being operated solely by the surviving cadet members of Red Squad. ()

A Federation troop convoy was instructed to maintain radio silence while they passed through the Badlands later that year. ()

The  was put under radio silence when it traveled to Romulus in 2375. ()

See also 
 Communications blackout

External link
 

de:Funkstille
Communications technology
Maneuvers