A role an agent may have. role Since roles have contexts and time constraints that are important to take into account (for example, a person can be author of one paper and reviewer of another, while another person will be editor of a journal only for a defined period, not for ever), the [PRO](http://port.org/spar/pro) and [SCoRO](http://purl.org/spar/scoro) ontologies permit these contexts to be specified, using the Time-indexed Value in Context ([TVC](http://www.essepuntato.it/2012/04/tvc/)) ontological design pattern. Thus, the domain of `pro:withRole` is not `foaf:Agent`, but rather a member of the class `pro:RoleInTime`, which itself is the range of the property `pro:holdsRoleInTime`, for which the domain is `foaf:Agent` (i.e., our contributor). All but three of the allowed values in the DataCite controlled list terms for contributor type are defined by individual members of the class `pro:Role` in [PRO](http://purl.org/spar/pro), or of its sub-classes in [SCORO](http://purl.org/spar/scoro): - `scoro:contact-person` (Contact Person) - `scoro:data-creator` (Data Collector) - `scoro:data-curator` (Data Curator) - `scoro:data-manager` (Data Manager) - `pro:distributor` (Distributor) - `pro:editor` (Editor) - `scoro:host-institution` (Hosting Institution) - `pro:producer` (Producer) - `scoro:project-leader` (Project Leader) - `scoro:project-manager` (Project Manager) - `scoro:project-member` (Project Member) - `scoro:registrar` (Registration Agency) - `scoro:registration-authority` (Registration Authority) - `scoro:researcher` (Researcher) - `scoro:rights-holder` (Rights Holder) - `scoro:sponsor` (Sponsor) - `scoro:supervisor` (Supervisor) - `pro:translator` (Translator) - `scoro:workpackage-leader` (Workpackage Leader) The remaining two, i.e., “RelatedPerson” and “ResearchGroup”, can be specified as a type (by means of the property `rdf:type`) of the contributor under consideration by means of the following classes respectively: - `foaf:Person` (Related Person) - `frapo:ResearchGroup` (Research Group) Note that many other individuals not required for DataCite metadata also exist within these [PRO](http://port.org/spar/pro) and [SCoRO](http://purl.org/spar/scoro) classes, e.g., `pro:copy-editor` and `scoro:principal-investigator`, and new individuals can easily be added to those ontologies, giving great flexibility. :silvio-peroni pro:holdsRoleInTime :contact-person-for-my-dataset . :contact-person-for-my-dataset a pro:RoleInTime ; pro:relatesToEntity :my-dataset ; pro:withRole scoro:contact-person . scoro:contact-person a pro:Role .