The objective was to understand how fanfiction narrative genres are classified in repositories, describing the users perceptions and motivations to accomplishthe indexing. The research is descriptive and exploratory, with the Intensive Direct Observation method in virtual groups of fans who write and consume fanfictions;the data supported a qualitative analysis of the fanfictions narrative genres used in theirindexingin digital repositories. The analysis demonstrated that many of narrative genres used in the repositories express concern with the representation of gender, sexual and physical aspects. Furthermore, natural language words, neologisms and other foreignwords are re-semantized to represent narrative genres. It was concluded that narrative genres are used to classify the stories, to express singularities andtogive representation to demands of marginalized groups of the publishing market.