Based on response from JC at NSIDC, the CADIS OAI DIF records do not validate against the DIF 9.4 schema. It appears that the element "Temporal_Coverage" is not in the correct sequence order.

Excerpt from email:

> (http://cadis.prototype.ucar.edu/oai/repository.htm?verb=ListRecords&metadataPrefix=dif)

The validation fails with this message:
NOT VALID:
cadis_20100623/oai%3Aaoncadis.org%3Aorg_nsf_aon_cadis_terrestrial_ecosystems_terrestrial_ceon_gateway_cadis.xml
 Error: cvc-complex-type.2.4.a: Invalid content was found starting with
 element 'dif:Temporal_Coverage'. One of
 '{"http://gcmd.gsfc.nasa.gov/Aboutus/xml/dif/":Personnel,
 "http://gcmd.gsfc.nasa.gov/Aboutus/xml/dif/":Discipline,
 "http://gcmd.gsfc.nasa.gov/Aboutus/xml/dif/":Parameters}' is expected.