Using a feministic perspective and a critical approach, my purpose is to discuss bibliographic classification, a central aspect of Library and Information Science. More specifically, my aim is to demonstrate the norms and the dominating thoughts regarding the organization and representation of knowledge, subjects, and social categories in classification systems. I review previous research involving critical approaches to classification. These show that classification systems are a reflection of the context in which they are created, with the result that universal assumptions can be questioned. Some studies also present problems inherent in hierarchical structures. Regarding feministic theories, I explain that they expose and criticize the male norm and the unequal division of power between men and women in society. By showing that our ideas of differences between the sexes are social constructions, feminists aim at changing normative and oppressive structures. Combining critical classification with feministic theories, I then analyze DDC and SAB. I find that the male, heterosexual, and western norm is manifested through the way the alternative is represented, on the one hand through its degree of explicit description, on the other through its position in the hierarchical structure. From a feministic viewpoint, the society described by the systems is a patriarchal one. I conclude by claiming that just as normative and oppressive structures in society can be changed, similar phenomena in classification systems can be avoided through raised awareness, an openness to diversity and ambiguity, and network technologies.