The Matchmaker warnings about missing metadata fields such as this one - Required metadata is missing: http://purl.org/dc/terms/created Edit Metadata - are not very helpful. Users have no way to know which metadata label corresponds to the predicate provided. Can the predicate be changed to labels and show predicate and description on hover?

Also, there is no information if the missing metadata term is included among the existing metadata terms or needs to be created (perhaps the instruction should say in this case that the Project Space admin needs to make this term available).