Using the Library of Congress Classification System 

All books in the Hartfield Library are identified by a unique call number.  These call numbers are assigned using the Library of Congress Classification System.  The Library of Congress System organizes materials in alphanumeric order.

The call number on the spine of a book contains at least three lines.  Each line should read distinctly and separately.  A typical call number might read as follows:

(Line 1) BS
                        (Line 2) 617
                        (Line 3) .L61
                        (Line 4) G3
                        (Line 5) 1981

Line 1.  The first line is always a single letter or a combination of letters.  When shelved, single letters are arranged first.  Double letters follow single letters.  The letters below are in correct order from left to right.

                        P            PN            PR            PS            PZ

Line 2.  The second line consists of numbers.  Books are shelved in numerical order from the lowest number to the highest number.  The call numbers below are in correct order from left to right.

BF                      BF                   BF
                        31                      310                  3105

Some numbers in the second line have a decimal point.  Examples are:

                        BF                      QC
                        30.5                   719.8

Books are shelved by the whole numbers first, then by the numbers following the decimal point.

BF                      BF                   BF                   BF
                        607                    607.2               6072                6072.5

Line 3.  Line three usually begins with a decimal point followed by a letter.  Books are shelved alphabetically by the letter.  A number always follows the letter.  When line three begins with a decimal point, the numbers are decimals -- not whole numbers.  Therefore, numbers in line three are filed digit by digit rather than by the whole number.  For example, .G39 is shelved before .G4 because .G4 really means .G40.  Since .G39 precedes .G40, .G39 would be shelved first.  The number .B765 is filed before .B77 because .B77 is .B770.  If you become confused, simply add a “mental” zero to a single digit when comparing it to a double digit.

The call numbers below are in correct order from left to right.

            BF                   BF                   BF                   BF                   BF
            706                  706                  706                  706                  706
            .A2                  .A276              .A28                .A281              .A29

Line 4.  Many call numbers are only three lines long.  If a fourth line is added, it will either be a four-digit number that reflects the date of publication (i.e., 1980, 1986) or a single letter followed by several numbers (i.e., W15 or H75).

When the fourth line has a letter followed by numbers, it is a continuation of the third line that began with a decimal point.  Although the fourth line will not begin with a decimal point, the numbers are decimals -- not whole numbers.  These numbers are filed like those in line three, digit by digit.  The call numbers below are in correct order from left to right.

BF                   BF                   BF                   BF                   BF
            706                  706                  706                  706                  706
            .A2                  .A2                  .A2                  .A2                  .A2
            G49                 G5                   G513               G52                 G521

Line 5 through the end.  A call number may consist of more lines containing dates and/or letter combinations.  Follow the instructions given for lines 1 through 4.