Linguacode is a universal language used during First Contact scenarios, often employed when the universal translator is unable to facilitate communication. The language was developed by noted communications officer Hoshi Sato in the 2160s. (ENT: "In a Mirror, Darkly, Part II")
In 2272, the Epsilon IX station transmitted linguacode friendship messages as the V'Ger cloud approached, but received no response. The station was subsequently absorbed by the cloud and destroyed. As the USS Enterprise intercepted the cloud, Captain Kirk ordered Communications Officer Uhura to broadcast greetings in Linguacode; again, V'Ger was unresponsive. The giant cloud then opened fire on Enterprise. Science Officer Spock concluded that V'Ger was unable to receive their "primitive" form of communication, which was too slow to be received. Spock adjusted their linguacode transmission to a frequency of more than one million megahertz, allowing V’Ger to receive and understand their messages of friendship. V’Ger then ceased its attack. (Star Trek: The Motion Picture)
Starfleet Mission Specialist Tam Elbrun suggested that linguacode was insufficient to communicate with the space-going lifeform Gomtuu in the year 2366. Elbrun believed that only "direct mind-to-mind" telepathic contact would suffice. A Template:ShipClass warbird hailed Gomtuu with what Commander Data described as a Romulan version of linguacode, but the Romulans received no response from the lifeform. (TNG: "Tin Man")