PassiveLogic Universität Bremen TZI The Semantic Definition Format (SDF) is a format for domain experts to use in the creation and maintenance of data and interaction models in the Internet of Things. It was created as a common language for use in the development of the One Data Model liaison organization (OneDM) definitions. Tools convert this format to database formats and other serializations as needed. An SDF specification describes definitions of SDF Objects and their associated interactions (Events, Actions, Properties), as well as the Data types for the information exchanged in those interactions. // A JSON format representation of SDF 1.0 was defined in version // (-00) of this document; version (-05) was designated as an // _implementation draft_, labeled SDF 1.1, at the IETF110 meeting of // the ASDF WG (2021-03-11). The present version (-11) collects a // few smaller changes as input to the 2022-02-28 ASDF WG interim. // It also removes deprecated elements from SDF 1.0.