> From: Code for Libraries [mailto:[log in to unmask]] On Behalf Of > Ross Singer > Sent: Friday, March 05, 2010 09:18 PM > To: [log in to unmask] > Subject: Re: [CODE4LIB] Q: XML2JSON converter > > I actually just wrote the same exact email as Bill (although probably > not as polite -- I called the marcxml "collection" element a > "contrivance that appears nowhere in marc21"). I even wrote the > "marc21 is EOR character delimited files" bit. I was hoping to figure > out how to use unix split to make my point, couldn't, and then > discarded my draft. > > But I was *right there*. > > -Ross. I'll answer Bill's message tomorrow after I have had some sleep :) Actually, I contend that the MARC-XML collection element does appear in MARC (ISO 2709), but it is at the physical layer and not at the structural layer. Remember MARC records were placed on a tape reel, thus the tape reel was the collection (container). Placed on disk in a file, the file is the collection (container). I agree that it's not spelled out in the standard, but the concept of a collection (container) is implicit when you have more than one record of anything. Basic set theory: a set is a container for its members :) The obvious reason why it exists in XML is that the XML infoset requires a single document element (container). This is why the MARC-XML schema allows either a collection or record element to be specified as the document element. It is unfortunate that the XML infoset requires a single document element, otherwise you would be back to the file on disk being the implicit collection (container) as it is in ISO 2709. Andy.