This document specifies the structure of an ontology for a fine-grained description of the expressive power of corpus query languages (CQLs) in terms of search needs. The ontology consists of three interrelated taxonomies of concepts: the CQLF metamodel (a formalization of ISO 24623-1); the expressive power taxonomy, which describes different facets of the expressive power of CQLs; and a taxonomy of CQLs.

This document specifies:

a) the taxonomy of the CQLF metamodel;

b) the topmost layer of the expressive power taxonomy (whose concepts are called “functionalities”);

c) the structure of the layers of the expressive power taxonomy and the relationships between them, in the form of subsumption assertions;

d) the formalization of the linkage between the CQL taxonomy and the expressive power taxonomy, in the form of positive and negative conformance statements.

This document does not define the entire contents of the ontology (see Clause 4).