This paper deals exclusively with e-lexicography. It intends to answer the question how much a lexicographer in charge of a new e-dictionary project should know about lexicographical structures, and how this knowledge could be communicated to the IT programmer designing the underlying database and the corresponding user interfaces. With this purpose, it first defines the concepts of lexicographical database, e-dictionary and e-lexicographical structure. Then it discusses some of the new ways in which lexicographical structures express themselves in the digital environment. It stresses, above all, their dynamic character and great complexity which make it extremely difficult and time-consuming for the lexicographer to get an overview of all the structures in an e-lexicographical project. Finally, and based upon the experience from the planning and design of five e-dictionaries, it shows how the lexicographer, nonetheless, can treat the question in the concrete interdisciplinary interaction with the programmer in order to obtain the database and interfaces needed to guarantee quality and innovation in an e-dictionary project.