1. A non-transitory computer readable storage medium encoded with computer program code such that, when said computer program code is executed by a processor, said processor performs a semiconductor device design method, said design method comprising: accessing design rules by interacting with a graphical user interface (GUI) by selecting a feature of a semiconductor device layout when said semiconductor device layout is displayed on said GUI, wherein said accessing said design rules automatically accesses a library of design features, and wherein the semiconductor device layout is used to form a photomask set.