IWebAnnotationResourceData is based on the "External Web Resource" type defined by the Web Annotation Data Model specification: https://www.w3.org/TR/annotation-model/#external-web-resources
While "id" property in an "External Web Resource" must be an IRI, Colibrio allows a URL, URI or URN as well.
A URL, URI, URN or IRI identifying the resource. May contain a fragment part.
IWebAnnotationResourceData is based on the "External Web Resource" type defined by the Web Annotation Data Model specification: https://www.w3.org/TR/annotation-model/#external-web-resources
While "id" property in an "External Web Resource" must be an IRI, Colibrio allows a URL, URI or URN as well.