The current DwC Terms [1] (carrying Identifier http://rs.tdwg.org/dwc/2015-03-19/terms/ and Date Modified: 2015-06-02 ) is confusing (confused? silent? ) about the relation of the "sister classes" to the terms intended (?) to be used therewith. For example, dwc:Event, dwc:MachineObservation, and dwc:HumanObservation could reasonably(?) all have dwc:eventDate applied to them. But http://rs.tdwg.org/dwc/terms/index.htm#eventDatesuggests Class=dwc:Event. Now it's human-clear that for each of the "multiple" boldface lines in the index, the second and subsequent terms are meant to be special cases of the left most one. What I can't see is whether [1] intends to encourage (require?) this in some explicit way, and where that explicit way is to be found. (I had a dream that the DwC RDF Guide might take a position....) . Thanks. --Bob p.s. I concede that some answers might lurk in the ongoing move of resources to http://tdwg.github.io/dwc/terms/. My second dream was that tdwg.github.io does Content Negotiation and curl would rescue me.... [1] http://rs.tdwg.org/dwc/terms/index.htm -- Robert A. Morris Emeritus Professor of Computer Science UMASS-Boston 100 Morrissey Blvd Boston, MA 02125-3390 Filtered Push Project Harvard University Herbaria Harvard University email: morris.bob@gmail.com web: http://efg.cs.umb.edu/ web: http://wiki.filteredpush.org http://wiki.datakurator.net http://taxonconceptexplorer.org/ http://www.cs.umb.edu/~ram