Galaxy Quadrant YX=12-114 was a region of space. This quadrant included Sector Z-6. Prior to stardate 1709, a tabulation of comets for this quadrant were collected into one book, which was named the Table of Comets. (TOS: "Balance of Terror")
This was the first named quadrant in Star Trek. This use of the term quadrant occurred before the current standardization of the quadrant/sector model of stellar cartography.