Searching by call number lets you identify works in a broader subject area without thinking of all the relevant subject terms or keywords.
To search by call number range, do a keyword search with this format:
for Library of Congress numbers, LC:
for National Library of Medicine numbers, NLM:
for Dewey numbers, Dewey:
for SuDoc numbers, GovDoc:
for GPO Item numbers, GPO Item No:
To retrieve things in a call number range, truncate the call number with an asterisk for each character in the root.
E.g, to search all the LC call numbers in the PT5000s, I'd search LC:PT5***
Searching WorldCat by library code allows you to identify works held by other institutions. This can be handy to compare our holdings with a peer institution or group of peers. You might use this to evaluate the comparative strength of our collection in an area, or to identify titles that we might want to add to our collection. You'll usually want to combine this with a call number or subject search and/or limit by publication year.
The search box for Library Code appears at the bottom of the WorldCat search screen. There is a link to "Find codes" adjacent to the search box.
The search will retrieve items held by the institutions searched, but displays all the holding libraries for those items, so you can readily see overlap with our own collection, or identify widely held titles. Our holdings are highlighted on the results page.
Beware of a couple of hazards: