Data from agricultural experiments represent a valuable resource that can be used to construct decision support systems or to study such issues as sustainability, climate change or treatment by environment interactions. However, they are usable only if all the relevant details are recorded in a secure and readily accessible way, and this is best achieved using an information system. Details to be stored include the physical properties of the units, the underlying structure of the design, the treatments studied in the experiment and their relation to the underlying structure. This relationship can succinctly be described for many designs by storing the generator used to construct the design. Possibilities include design keys, design splits, alpha arrays and initial blocks of cyclic designs.