The concept of personal or moral norms is ambiguous with regard to its motivational content. An extension and a refinement of the norm taxonomy are therefore suggested, distinguishing between two types of personal norms: introjected and integrated norms. A preliminary assessment of the taxonomy is carried out based on a survey of residents of Denmark. A range of norm constructs were measured with regard to four environmentally responsible behaviours: buying organic milk, buying energy saving light bulbs, source-separating compostable kitchen waste, and using public transportation for work and shopping. Also the frequency of the four behaviours was measured. The revised taxonomy has content, discriminant, predictive, and nomological validity and satisfactory test-retest reliability. The most internalized of the new norm constructs, integrated norms, is most strongly correlated with conventional measures of personal and moral norms. However, other constructs in the proposed taxonomy still contribute significantly to predicting conventional norm measures after controlling for integrated norms. This documents the motivational ambiguity of the conventional personal norm construct. The patterns of correlation between norm constructs and between norms and behaviour vary between behaviours. Hence, respondents seem to apply different norms for different environmentally responsible behaviours.