Introduction: Text genres used by so-called information organizers in the processes of information organization in information systems were explored in this research. Method: The research employed text genre socio-functional analysis. Five genre groups in information organization were distinguished. Every genre group used in information organization is described. Empirical evidence for genre group two was obtained through specific analysis of genres used by cataloguers cooperating within the Polish union catalogue. Analysis: A qualitative genre analysis concerning the choice and description of five groups of genres most important for information organization was carried out. Most attention was paid to the second group of text genres, consisting of vocabularies and rules used in cataloguing. Results: The text genre system used in information organization and showing the roles of any specified text genre group is described. The case of the Polish union catalogue database helped to present temporo-spatial dependencies appearing in the regulated genre system. Conclusions: Information organization involves the creation of representations of published texts with a variety of text tools. The creation of these texts and their use (reading) results in individual knowledge reorganization (modification) of all people involved in these processes, that is both writers (including authors of vocabularies, cataloguing rules and bibliographic records) and readers. [Paper presented at the Information Seeking in Context (ISIC): The Information Behaviour Conference, Part 1 (11th, Zadar, Croatia, September 20-23, 2016).]