Because of their strong economic impact, complexity and maintainability are among the most widely used terms in software engineering. But, they are also among the most weakly understood! A multitude of software metrics attempts to analyze complexity and a proliferation of different deffinitions of maintainability can be found in text books and corporate quality guide lines. The trouble is that none of these approaches provides a reliable basis for objectively assessing the ability of a software system to absorb future changes. In contrast to this, relational database theory has successfully solved very similar dif- ficulties through normal forms. In this paper, we transfer the idea of normal forms to code. The approach taken is to introduce semantic dependencies as a foundation for the definition of code normal form criteria.