Understanding Call Numbers

For Library of Congress call numbers, read the first line alphabetically (Think ABC Order).

Notice that LA comes before LB.

The second line is read numerically. (Think 1, 2, 3...)

Notice that 8777 comes before 8778.

The third line is a mixture of the first two lines AND the numbers in this line are read as decimals.

R comes before S

What if the 3rd line starts with the same letter?

The number on the 3rd line is read as a decimal. Though 633 looks larger than 64, you have to fill in the missing decimal place with a 0.

633<640

The last line is read numerically. (Remember: 123)

1982 comes before 1995.