PassiveLogic Universität Bremen TZI Ericsson 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. 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. Tools convert this format to database formats and other serializations as needed. // 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 (-15) adds a number // of editorial improvements and an example for removing an // affordance from a target referenced via sdfRef.