Access during COVID-19

Weaver Library is open Sunday through Thursday 9am-9pm, and Friday and Saturday 9am-5pm. You can also contact us by chat, text, and email during those hours. We’re providing limited services in the Main Library lobby. The Health Sciences Library is open to Health Sciences affiliates. Learn more about access during COVID-19.

How to read call numbers

Most of our materials are organized on the shelf using Library of Congress call numbers. When looking at the number on the book spine, these would be read one line at a time.

For example:


Start with line 1

Books are arranged in alphabetical order, by the letters on the first line of the call number.

For example, first come all the D call numbers, then all the DA call numbers, then DB, etc.

 D; DA; DB

Look at line 2

Within the DA call numbers, books are arranged in number order.

The numbers are arranged in numerical order, from low to high.

 1; 2; 22; 36; 38

Line 3

Line 3 of the call number has a letter and a number. The letters are in alphabetical order.

Once you find the letter, read the number. But note these are decimals not whole numbers.

Example: A55 is read as A .55. This is why A55 comes before A6 (A .55, A .6, A .65).

Note: Sometimes there will be a fourth Cutter number to further differentiate by author, title or subject or the year of publication. If there are multiple copies of the book, that may be indicated as well. 

 A5; A55; A6; A77; B21; B212