Much work is currently being done in the area of national and international data communications and computer networking standards. One highly visible activity is being conducted by the International Organization for Standardization (ISO) and the American National Standards Institute (ANSI) to develop standards for Open Systems Interconnection (OSI). However, most Local Area Network standards work to date has dealt exclusively with the Physical and Data Link Layers (Levels 1 and 2) of the ISO architecture. Upper level standards must be developed to fully meet the applications needs of network users. These upper level standards and protocols can provide such services as character echoing, error control, source/destination addressing, and encryption. Full specification of these and other upper level protocols is essential to the development of heterogeneous multi-vendor document retrieval systems.