Abstract: An interactive trade network is described that integrates distributive messaging using a host computer and telecommunication networks, real-time interactive communications, a hierarchical knowledge matrix containing two familiar and comprehensive indices of classes of goods and classes of establishments and a legend of trade-related, cross-reference terms or parameters, a multiline programmable application, an integrated application program interface, and integrated application programs. The Host System uses each Index Number of each of the indices as a topic board name. The apparatus creates a highly-selective media for either (a) messaging on mutually exclusive indexed topics of trade or (b) engaging in pubic or private real-time conferencing or electronic mail dedicated to any class of indexed economic activity. It enables progressive discussions on, and the retrieval of just the information needed under, discrete indexed topics on trade instantaneously.