Information technology -- General-Purpose Datatypes (GPD)

ISO/IEC 11404:2007 specifies the nomenclature and shared semantics for a collection of datatypes commonly occurring in programming languages and software interfaces, referred to as the General-Purpose Datatypes (GPD). It specifies both primitive datatypes, in the sense of being defined ab initio without reference to other datatypes, and non-primitive datatypes, in the sense of being wholly or partly defined in terms of other datatypes. The specification of datatypes in ISO/IEC 11404:2007 is "general-purpose" in the sense that the datatypes specified are classes of datatype of which the actual datatypes used in programming languages and other entities requiring the concept "datatype" are particular instances. These datatypes are general in nature; thus, they serve a wide variety of information processing applications.

ISO/IEC 11404:2007 expressly distinguishes three notions of datatype:

the conceptual, or abstract, notion of a datatype, which characterizes the datatype by its nominal values and properties;
the structural notion of a datatype, which characterizes the datatype as a conceptual organization of specific component datatypes with specific functionalities; and
the impleme