Space data and information transfer systems — Data entity dictionary specification language (DEDSL) — Abstract syntax

ISO 21961:2003 gives requirements and defines the syntax of a specification language to be used in the creation of a data entity dictionary (DED).

A data entity is a concept that can, or does, take on one or more values. Semantics of a data entity, such as a text definition of its meaning, are defined by attributes. The purpose of ISO 21961:2003 is to define a language for specifying a dictionary which describes semantics for a collection of data entities; it does not define a specific dictionary. A dictionary is understood as a mechanism that is able to organize a set of information in a consistent and easily understandable manner, and it is commonly used by humans to look up the meaning of words used in natural languages. Similarly, a data entity dictionary (DED) is used by humans and systems to look up the definition, and other attributes, of data entities used in the definition and generation of data products.

ISO 21961:2003 defines the abstract definition of the semantic information that is required to be conveyed and presents the specification in a layered manner (attributes, entities, dictionaries). This is done so that the actual technique used to convey the information i