The document summarizes the key differences between Everest Series Maps currently used by the Indian military and the new Defence Series Maps (DSM) being introduced to replace them. The DSMs follow an international numbering system compared to the complex system used in Everest Maps. They also use updated military grid zones, projection and datum in line with GPS. While content and accuracy remains the same, the DSMs have different map sheet layout and numbering, as well as some updated symbols. Software has been developed to enable easy conversion between the grid references of the two map series.