The phrase "Schema Definition Warning" only occurs once in the published 1.0.4 spec (without respect to capitalization), in Section 2.6 Specific Errors Classified: "Note: Unrecognized DFDL properties or property values can produce a Schema Definition Warning and an implementation can attempt to process data despite the warning." Is the concept of a Schema Definition Warning a nascent concept already present in the spec but not well-defined? If so, this might be a minor issue that warrants an errata. My recommendation would be that Schema Definition Warning be defined and used consistently throughout the document. Otherwise, I recommend that "Schema Definition Warning" be replaced in the above sentence with simply "warning". In this case, this is probably just an editorial issue. Very respectfully, -- Jonathan W. Cranford Senior Information Systems Engineer The MITRE Corporation (http://www.mitre.org)