  While the general analysis of named entities has received substantial
research attention on unstructured as well as structured data, the analysis of
relations among named entities has received limited focus. In fact, a review of
the literature revealed a deficiency in research on the abstract
conceptualization required to organize relations. We believe that such an
abstract conceptualization can benefit various communities and applications
such as natural language processing, information extraction, machine learning,
and ontology engineering. In this paper, we present Comprehensive EVent
Ontology (CEVO), built on Levin's conceptual hierarchy of English verbs that
categorizes verbs with shared meaning, and syntactic behavior. We present the
fundamental concepts and requirements for this ontology. Furthermore, we
present three use cases employing the CEVO ontology on annotation tasks: (i)
annotating relations in plain text, (ii) annotating ontological properties, and
(iii) linking textual relations to ontological properties. These use-cases
demonstrate the benefits of using CEVO for annotation: (i) annotating English
verbs from an abstract conceptualization, (ii) playing the role of an upper
ontology for organizing ontological properties, and (iii) facilitating the
annotation of text relations using any underlying vocabulary. This resource is
available at https://shekarpour.github.io/cevo.io/ using https://w3id.org/cevo
namespace.
