You do not have to understand the meaning of call numbers. Just remember to always WRITE DOWN THE LIBRARY & LOCATION AND THE COMPLETE CALL NUMBER.

Read Library of Congress call numbers one line at a time.These books would be shelved in the following order: 

First line, read alphabetically  Second line, read as a whole number  Third line, read alphabetically then as a decimal number  Final lines, read alphabetically then numerically

D 1 .A15

D 9 .A2 2005

D 25 .A1 W570 1982

DA 1 A1

Books are arranged on the shelf in alphabetical order, by the letter(s) on the first line of the call number. The first line represents the subject area and can be a single letter, double letter or three letters.

Example: First come all the D call numbers, then all the DA call numbers, then DB, etc.

After matching the correct letters on the first line read the second line. The second line is always a number from 1 to 9999 and may include decimals. The numbers are arranged in numerical order, from low to high.

Example: On the second line 36.3 comes before 36.78

When the first two lines are identical, read the third line. The third line is the trickiest part of the call number. Line 3 has a letter and a number. The letters are filed in alphabetical order. Then the numbers that follow are filed in ascending decimal order. This means that .R49 is smaller than .R5 and would appear first on the shelf.

Example: On the third line .A55 is read as A .55 - this is why .A55 comes before .A6

The final line(s) may be an alphanumeric combination, publication date or a volume indicator. These
lines are read alphabetically then numerically.