Here's a quick guide on how to read call numbers in our library (and most other academic libraries).
The first line is read in alphabetical order.
ex. PN would be before the PQ's but after the PM's.
Read the second line in numerical order.
ex. PN 6747 would be after PN 6746 and before PN 6747.1 or PN 6748.
The third line is tricky. Read the letter in alphabetical order then the number as a decimal.
ex. PN 6747 .S245 would come before PN 6747 .S5, because .5 in decimal is really .500!
Sometimes the fourth line will have another combination of letter and numbers, and you read it exactly like the other line.
ex. PN 6747 .S245 P4713 would come before PN 6747 .S245 P8, because .8 in decimal is really .800!
When you see a line near the bottom that looks like a year, it is a year! This goes in numerical order.
ex. If there was a book just like this except the date was 2003, it would go before the 2007 edition.
You could think of a call number like a detailed address in reverse: planet, country, state, city, street, street number. Each line helps you narrow down the book's exact location!
