KTC Control AB Universität Bremen TZI Ericsson The Semantic Definition Format (SDF) is concerned with Things, namely physical objects that are available for interaction over a network. SDF is a format for domain experts to use in the creation and maintenance of data and interaction models that describe Things. An SDF specification describes definitions of SDF Objects/SDF Things and their associated interactions (Events, Actions, Properties), as well as the Data types for the information exchanged in those interactions. Tools convert this format to database formats and other serializations as needed.