At least at first lexicography was not one of UZEI's goals. However, in 1986 this department was set up due to the lexicographical work that was then beginning to be undertaken by a team as support for the Royal Academy of the Basque Language (Euskaltzaindia). The Academy's Lexicography Commission saw the need for a corpus that reflected modern Basque and UZEI was tasked with creating it. Since then, in addition to inventorying everything that is published in Basque and using it to complete the statistical sampling which has become the basis for the corpus, the Lexicographical Department has been drawing up reports about the history of the forms to be dealt with by the Academy's Commission.