The main objective of design rule checking (DRC) is to achieve a high overall yield and reliability for the design. If design rules are violated the design may not be functional. To meet this goal of improving die yields, DRC has evolved from simple measurement and Boolean checks, to more involved rules that modify existing features, insert new features, and check the entire design for process limitations such as layer density. A completed layout consists not only of the geometric representation of the design, but also data that provides support for the manufacture of the design. While design rule checks do not validate that the design will operate correctly, they are constructed to verify that the structure meets the process constraints for a given design type and process technology.