In the programming area much attention is given to recursion, but this technique is hardly considered in the data modeling area. This paper discusses a case study about storing project data of a knowledge-based application called Quaestor, in which the modeling of a recursive data structure is the central issue. Data modeling methods such as entity-relationship modeling or object oriented modeling are not yet equipped with concepts for dealing with recursive data structures. Some fact oriented modeling methods however can deal with recursion. In this case study, Fully Communication Oriented Information Modeling (FCO-IM) is used to capture the complex identification problem of the recursive structure of Quaestor project data.