Chicago-The Graphic Communications Association has announced creation of a Web-based numbering system for production of advertising and publishing materials. The GCA, Alexandria, Va., said the so-called Universal Advertising Digital Identifier (UADI) will aid advertising agencies and publishers in tracking insertion orders and allow them to tie transactions to specific advertisements. The move anticipates more widespread use of the Internet as a vehicle for distributing advertising campaigns and conducting transactions within electronic marketplaces, the GCA said. The proposed numbering system was developed by the GCA with help from publishing industry software developer Intersect Technologies Inc., Chicago. A Web site is scheduled to go live on Oct. 15 at www.uadid.org.