Belt

In conventional geodetic cartography, a belt 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 transverse Mercator projection.

Since World War II, the "belt" has been commonly replaced with "zone" - a term originally associated only with the Lambert conformal conic projection.