Defining covert rules as the unaware rules or illegitimated rules, this paper focuses on an age-old problem in China: the discrepancy between the name and the reality.

An algorithm of DNA computing is designed for minimum assignment problems,in which after planar decision-making variable and planar benefit value are compiled in DNA sequence through specific DNA encoding,all feasible solutions are gained with hybridization experiment and separating experiment,and then all optimization solutions are obtained with electrophoresis experiment and checking experiment.