Contains the directories for the United Nations Standard Messages (UNSMs) issued by the UN/ECE WP.4 periodically. Also provided are the supporting directories for UN/EDIFACT messages, segments, composite data elements, data elements and code list together with the syntax rules (ISO 9735), syntax implementation guidelines and message design guidelines. These directories are available on HD 3 1/2" diskettes as ASCII text files. Hardware requirements are IBM PC/XT/AT for compatible environments. These publications are identical with and have been reproduced from the United Nations Trade and Data Interchange Directory (UNTDID).