Unit XY-75847 was an entity aligned with Starfleet that reported detecting a Klingon fleet in their sector following the outbreak of the Federation-Klingon War in 2267. This information was also relayed to the USS Enterprise as she arrived at Organia, but the warning did not include the Klingon fleet's bearing in relation to the Enterprise.

The warning induced Captain Kirk to give Lieutenant Sulu specific orders regarding confrontation with the Klingon fleet: "do not fight – run, and return with the fleet." (TOS: "Errand of Mercy")