http://www.w3.org/TR/shacl-ucr/ I don't know if I've mention this before, but the acronym for the standard is SHACL - for Shapes Constraint Language. I'll now take another pass at Antoine's linking of DCMI requirements and SHACL requirements, and will also keep in mind the question of core. W3C has talked about the need for a core, but hasn't defined one, so many be can contribute to that. kc -- Karen Coyle [log in to unmask] http://kcoyle.net m: 1-510-435-8234 skype: kcoylenet/+1-510-984-3600