Design errors generated employing a mask rule check (MRC) program are indexed and examined one by one by an automated computer program connected to a false error pattern database that contains previously known waivered patterns, a real error pattern database that contains previously known pairs of an error-containing pattern and a corresponding error-free pattern, and optionally a mask house rule database. A waiver is applied to each design error for which a matching pattern is found in the false error pattern database. Each design error for which a match is found in the real error pattern database is modified to substitute an error-free pattern for an error-containing pattern therein. The output of the automated program includes a list of design errors for which no solution is found by the automated program.