The specification is not entirely clear on a the following points a) If the input document contains too many occurrences of an element, should that be treated as a validation error, or a processing error? Section 5.2.1 says "It is a parse error when an array is found to have a number of occurrences not conforming to the minOccurs and maxOccurs constraints in the absence of a default value specification. Note that specifically, this is not a validation error, it is a processing error" Points to note: - When unparsing, the infoset might omit an element which has minOccurs > 0. Should that be reported as a validation error, or a processing error? - When unparsing, the infoset might omit an entire group. If all of the elements in the omitted group were optional, should this be considered an error ( because groups are implicitly required ) or not? - When parsing an unordered group, if the input document contains more than maxOccurs occurrences of one of the members, is that a processing error or a validation error? The specification seems to imply that it is a validation error, but that seems inconsistent with section 5.2.1 It may be necessary to include a section which specifies how the DFDL processor should perform schema validation. regards, Tim Kimber, Common Transformation Team, Hursley, UK Internet: kimbert@uk.ibm.com Tel. 01962-816742 Internal tel. 246742 Unless stated otherwise above: IBM United Kingdom Limited - Registered in England and Wales with number 741598. Registered office: PO Box 41, North Harbour, Portsmouth, Hampshire PO6 3AU