Language resource management — Feature structures — Part 2: Feature system declaration

ISO 24610-2:2011 provides a format to represent, store or exchange feature structures in natural language applications, for both annotation and production of linguistic data. It is ultimately designed to provide a computer format to define a type hierarchy and to declare the constraints that bear on a set of feature specifications and operations on feature structures, thus offering means to check the conformance of each feature structure with regards to a reference specification. Feature structures are an essential part of many linguistic formalisms as well as an underlying mechanism for representing the information consumed or produced by and for language engineering applications.

A feature system declaration (FSD) is an auxiliary file used in conjunction with a certain type of text that makes use of fs (that is, feature structure) elements. The FSD serves four purposes. 1) It provides an encoding by which types and their subtyping and inheritance relationships can be introduced and defined, thus laying the basis for constructing a feature system. 2) It provides a mechanism by which the encoder can list all of the feature names and feature values and give a prose description as t