[tdwg-tapir] Requesting available darwin core elements from data provider

Hi, Is there a way to request from a tapir data provider which optional elements of the darwin core schema are actually implemented by the provider in question. I mean, if I understood correctly only a small subset of the Darwin Core are required (GlobalUniqueIdentifier,DateLastModified,BasisOfRecord,InstitutionCode,CollectionCode,CatalogNumber,ScientificName). It would be nice to know what optional elments a given provider implements before formulating a search request to that provider (for instance, whether information defined in the IslandGroup element is available). The metadata response does not provide this information, I think. Thanks a lot. Tomas bar