 A fully conforming instantiation of an element set for a particular community, created to adapt an element set into a package tailored to the functional requirements of a particular application while retaining interoperability with the base standard. Can involve mixing and matching terms from multiple standards to meet the descriptive needs of a particular project or service. [General Dictionaries] 
application programming interface 
n., (API) A set of routines, protocols and tools for building software ap