This essay is dealing with the difficulties of cataloging and classifying anonymi and other kinds of literature without the components which have set the norm for bibliographic cataloging, i.e. a defined author, a standardized title etc. A typical example of this kind of literature is folklore and folktales, which are dealt with thoroughly here. The character of and the society's historical view upon the folk literature, as literature considered, are being described, as is the evolution of rules for cataloging in general. The folk literature is mostly systematized after a different pattern from other literature, since bibliographical facts are often missing. Therefore, this essay looks upon the ”ethnological” classification of tales and folklore, which means the thematic sorting of motifs in the plots of different tales, which is the most common method of organizing folk literature. The main purpose of this ethnological classification becomes in other words more or less the same as the purpose of bibliographical cataloging nowadays, namely a purpose of facilitating the retrieval of a certain literary unit and a certain common motif of several tales respectively. As the most successful attempt in the area of classification of folk literature (mainly ethnological) is mentioned the work by the Finnish researcher Antti Aarne, ”The Types of the Folktale : a Classification and Bibliography” from 1910, revised and enlarged by Stith Thompson in 1961. / Uppsatsnivå: D