Zone

In conventional geodetic cartography, a zone is a two-dimensional orthogonal cartesian system used to plot a graticule where the projection belongs to the conformal/orthomorphic class. Specifically, a belt refers to a geographic area intended to be associated with a set of parameters and central meridian used with a conformal Conic projection.

Since World War II, the "zone" - has been used to define areas of intended coverage for large scale topographic and military mapping systems, regardless of the projection type used for the graticule.