Abstract: A taxonomic classification system includes a user computer, server, and optional register, which are networked together. A server contains data earmarked to be sent to the user, and server data. A user agent requests a server agent to send to the user computer a portion of the earmarked data or the server data that is covered by, or matches, the user's classification data. A register includes a database containing user and server classification data and optional respective reference data. The user agent or sever agent query the database through the register agent, which sends back user classification data, server classification data and/or respective reference data in response to the query.