Sector 97 is a region located near Federation space where a black cluster is located.
Starbase 514 was located in or near the sector, and the Breen reportedly had outposts in the sector as well.
In 2367, the USS Enterprise traveled to Sector 97 to locate the SS Vico, which was charting the cluster, after its home base lost contact with the science vessel. (TNG: "Hero Worship")