1. An image forming apparatus for dealing with videotex codes consisting of a sequential arrangement of geometric codes representing individual image areas as respective geometric drawings and also characteristic codes representing attributes of said geometric drawings, said apparatus comprising: means for effecting transmission of said geometric codes and characteristic codes; an order table for supervising the order of transmission of said geometric codes and characteristic codes; a characteristic code table communicating with said order table and enabling selection of said characteristic codes; and means for analyzing data in said tables and effecting changes therein.