PDF/A developers and users should be aware of a couple of important corrections that are going to be made to the metadata specifcations for PDF/A.
The PDF/A specification requires that certain metadata be written into conforming PDF/A files. This metadata is in XML, and more specifically uses the Adobe XMP specification. Unfortunately the published version of PDF/A had some errors and ambiguities in the specification of that metadata. This may lead to some tools producing PDF/A that is not strictly compliant with PDF/A (either as originally published or as corrected) or to some tools declaring files non-compliant when they are compliant.