Sector 71527 was a region of space. This sector contained the McAllister C-5 Nebula and the Federation-Cardassian border.

In 2369, the Reklar had a rendezvous with the USS Enterprise-D in Federation space. During this rendezvous, the Enterprise scanned the Reklar. This scan revealed that the warp nacelles of the Reklar had experienced a recent exposure to a molecule dispersion field. Working together, Captain Edward Jellico and Chief Engineer Geordi La Forge came to the conclusion that the Reklar had been in the nebula and that there might be Cardassian warships hiding in the nebula. A star chart of this sector was used during their deliberation. (TNG: "Chain of Command, Part II")

The map was changed for the remastered episode. The most notable change was the sector number, which was changed from Sector 21527 to Sector 71527.