A few years ago, there was some work being done in Portugal for UNIMARC and MARC21 validation via XML schemas: http://www.bookmarc.pt/unimarc/ http://www.bookmarc.pt/documentation/marcdoc.html Cheers, Keith On Mon, Feb 15, 2010 at 2:14 PM, Houghton,Andrew <[log in to unmask]> wrote: > Does anybody know whether the MARC formats ... are encoded in > an XML format that one might use for processing/validation of the > leader, field tags, indicator codes, subfield codes, field and subfield > repeatability, and field and subfield requiredness.