A call number is where you can find a book in the library. Pfeiffer Library uses Library of Congress to classify its books by call number. You can find a call number on the spine or on the front cover of the item.
The call numbers organize the items based on their contents, so items that have similar subject matter will be near each other. When you find a call number, you use it to locate the item on the self.
Call numbers have various parts that affect how you read it. Each section of the call number can be a new line to make it easier to read and understand. This is with the exception of the first 2 parts, which are typically placed together. Here is an example:
This tells you the subject matter. It keeps books of the same subject near each other. You read this alphabetically so O comes before P and P comes before PA.
You read this as a whole number, so 151 before 152 and etc. Typically you will see it placed on the same line as the starting letters.
This is where it starts to get tricky. Begin alphabetically, just as before. Then begin to read it as a decimal. Rather than reading it as 56 read it as 5 & 6. Therefore .M6 would come after .M56, because 5 comes before 6.
You read this line the same as the line above it, alphabetically and as a decimal.
This is the publishing year of the item. Read it as a year.
v.1 or c.2
Sometimes after the year you see v.1, v.2, etc or c.2, c.3, etc. 'V' is for volume and is included for items that are part of a multi volume set. 'C' is for copy, which indicates which library copy it is when multiple copies are owned.
Additionally, sometimes you may see 'REF' before a call number or 'Fac' after a call number. These are location indicators. For more information about location indicators, or finding an item in the library, please see locating an item.
Want more help? Try this video!
Want to learn more about LC subject organization? Try this link!