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Using the Call Number System

Interpreting LC Call Number Information

Each line of the call number represents a separate piece of information relating to the item.

  • The first line identifies the general LC subject designation.
  • The second line identifies the specific LC subject.
  • The next line(s), identify the author/main entry information.
  • The following line(s) contain item specific information, such as the year the item was published or the collection copy number.  Not all items contain these line(s).

This information is used to find an item's exact location in the stacks.

This link is to a document on the Library of Congress website that provides detailed information about the subordinate subject headings within each major subject:

Finding a Call Number in the Library Catalog

To find a known item in the Libraries' catalog:

  • Perform a title, author, or keyword search.
  • Select the item you want.

Webpage of information on catalog record for book with call number and "text me this call number" circled.

Once at the item record, locate the call number below the description of the book (marked with red oval).

Note that though the LC call number appears horizontally in the online record, it will appear vertically on the item's book label.  The call number in the example above would look like this:

Also note the Location of the item next to the call number in the catalog display, "Coe Library Stacks - Level 3."  The Geology Library, the Library Annex, the Rocky Mountain Herbarium Library, and the Law Library also house items with LC call numbers.  Additionally, media items, folios, portfolios, reference materials, and journals are all shelved in specific areas in the stacks--labels above the call number indicate separate locations. If you need assistance finding these collections, please visit the Help Desks of any of the UW Libraries.

To save you time, look at the item's Status.  If it doesn't say AVAILABLE then it's not in the stacks.  Go back to your original search to see if we own another copy, borrow it from another library using the Request It, or pick another title.

You need to copy down the entire call number or use the handy button at the individual record, entitled Text me this call # (blue oval) to send it to your mobile device.

You are now ready to search the stacks.

Where Is My Item?

Refer to the "Where is my Call Number?" guide shown below to find you item's location in the stacks.  Copies of this guide can be obtained at the Help Desks in all UW Libraries.

Chart for locating call number. Call number: A through E. Branch location: Coe Library. Level 1. Call number: F through H. Branch location: Coe Library. Level 2. Call number: J through PQ. Branch location: Coe Library. Level 3. Call number: PR through QD. Branch location: Coe Library. Level 4. Call number: QE. Branch location: Brinkerhoff Geoogy Library. See branch map for level. Call number: QF through S. Branch location: Coe Library. Level 4. Call number: T through Z. Branch location: Coe Library. Level 5.

Using the LC Call Number System

Think of an LC call number like an address. To find your item in the stacks, begin with the first line.

  • All items are shelved alphabetically by the letter(s) of this line.  This means that all A's will come before all B's, which will come before all C's, etc.
  • Items are then arranged in numeric order by the number(s) on the next line.  These numbers are read as whole numbers, which means that 7 would come before 33.
  • The following line(s) contain alpha-numeric information.  These lines are arranged alphabetically first, then decimally by the number that follows.  Since these numbers are read as decimals, .A33 would come before .A7See the figure below.

Diagram of call number label. 1. Books are shelved alphabetically by the first letter or letters. 2. Books are then arranged numerically by the number following the letter(s). 3. Finally, books are shelved alphabetically by the next letter and decimally by the following number.

Finally, as mentioned above, some call numbers contain additional line(s) that list other item specific information such as the publication year, volume, or copy number or the item.  These are shelved according to the "nothing before something" rule.  For example, an item without a publication date would come before an item with a publication date.

What If You Can't Find an Item?

If you followed our directions and you can't find the call number you want, contact Help Desk staff.