comment "Definition: This is a placeholder for classes, used for annotating the "Entity" and its subclasses. Mostly, these are not an "Entity" themselves. Examples include references to external databases, controlled vocabularies, evidence and provenance.
Rationale: Utility classes are created when simple slots are insufficient to describe an aspect of an entity or to increase compatibility of this ontology with other standards.
Usage: The utilityClass class is actually a metaclass and is only present to organize the other helper classes under one class hierarchy; instances of utilityClass should never be created." (string)