Check the regexp that Google uses in their call number normalization:

	http://code.google.com/p/library-callnumber-lc/wiki/Home

You may want to remove the prefix part, and allow for a fourth cutter.

The folks at UNC pointed me to this a few months ago.

-Tod

On Mar 31, 2011, at 11:29 AM, Jonathan Rochkind wrote:

> Does anyone have a good regular expression that will match all legal LC 
> Call Numbers from the LC Classified Schedule, but will generally not 
> match things that could not possibly be an LC Call Number from the LC 
> Classified Schedule?
> 
> In particular, I need it to NOT match an "MLC" call number, which is an 
> LC assigned call number that shows up in an 050 with no way to 
> distinguish based on indicators, but isn't actually from the LC 
> Schedules.  Here's an example of an "MLC" call number:
> 
> "MLCS 83/5180 (P)"
> 
> Hmm, maybe all MLC call numbers begin with MLC, okay I guess I can 
> exclude them just like that. But it looks like there are also OTHER 
> things that can show up in the 050 but aren't actually from the 
> classified schedule, the OCLC documentation even contains an example of 
> "Microfilm 19072 E".
> 
> What a mess, huh?  So, yeah, regex anyone?
> 
> [You can probably guess why I care if it's from the LC Classified 
> Schedule or not].

Tod Olson <[log in to unmask]>
Systems Librarian
University of Chicago Library