In taxonomy, descriptive data takes a number of very different forms. The goal of the Structured Descriptive Data (SDD) standard is to allow capture, transport, caching and archiving of descriptive data in all of its varied forms, using a platform- and application-independent, international standard. Such a standard is crucial to enabling lossless porting of data between existing and future software platforms including identification, data-mining and analysis tools, and federated databases.