In 2366, the Federation starship USS Enterprise-D detected a Romulan scout ship in the Romulan Neutral Zone. This outpost confirmed the presence of the scout ship and sent a message to the Enterprise-D. After receiving intelligence from a Romulan defector about a possible Romulan base at Nelvana III, this outpost received a warning from Starfleet Command. (TNG: "The Defector" ) According to Star Trek: Star Charts (p. 66), Sierra VI was one of a series of outposts codenamed Sierra along the Romulan Neutral Zone. These outposts were located in the Kaleb (Sierra) sector in the Beta Quadrant.