Karen Coyle wrote: <snip> I'm not sure how you calculate this. There are only 9 single-digit numbers (0-8, since 9 is for local use only), and most of them have already been used: 0, 2, 3, 4, 5, 6, 7, 8. A decision was made early on that the number subfields, to the extent possible, would retain the same meaning in each field in which they were used.
Perhaps you were thinking about using upper case letters, which would indeed give us 26 more options. That has been suggested many times at MARBI and never accepted even for discussion. The MARC record structure would allow the use of more than one character for the subfield code, e.g. "aa" instead of just "a". (Up to 9, BTW, since it's a one byte numeric field). That would give us scads more possibilities, but would require a lot of coding changes for software that processes MARC records. The number of characters in the subfield code is encoded in the leader, so we could actually mix 1-char and 2-char records in a single dataset, but most code that reads and writes MARC doesn't use that Leader byte to control the number of characters -- we tend to assume "1". </snip> Of course, this all assumes continuing the completely 100% obsolete ISO2709 format from the 1960s. For example, is the Unicode set valid for subfield codes? If not, why? Why can't we have a subfield lambda or rho? Why not a Chinese character or Church Slavic? If these were allowed, then we would have 1,114,112 possibilities, according to the high authority of Wikipedia http://en.wikipedia.org/wiki/Mapping_of_Unicode_characters. That should be enough. The answer is, such a suggestion is ridiculous since not everybody understand Chinese or Church Slavic. I agree, so the obvious question is: why do we have to be stuck with ISO2709 and single subfield codes? The instant we switch to an XML structure, even MARCXML, we can begin to add "subfield codes" that are 2, 3, 4, 5 or as many characters as we would like. It's time to get rid of the leader, the directory and the entire structure of the ISO2709 record. It served its time but has long been detrimental to the further development and sharing of library metadata. I still don't understand. Here we are discussing changing cataloging rules (well, not so much the procedures, but the numbering and structure of the rules) spending money so that every cataloger will have to be retrained and catalogs will have to be retooled; yet this lousy ISO2709 format seems to be sacrosanct. Why? It absolutely must be dumped overboard, and the sooner the better. James L. Weinheimer j.weinhei...@aur.edu Director of Library and Information Services The American University of Rome Rome, Italy First Thus: http://catalogingmatters.blogspot.com/