Library of Congress:
Library of Congress Call Number
Reading a Library of Congress Call Number
A Library of Congress call number is made up of letters and numbers. This "LC Classification System" was developed by the Library of Congress. The letter and number system will expand to easily include a new subject when new information is discovered. Most schools and public libraries use the Dewey Decimal Classification System, but frequently colleges and universities use the " LC " system.
First Row -- Letters
The first row of letters in a basic Library of Congress call number represents a subject area. For instance, call numbers beginning with an "M" would be some type of music, and call numbers beginning with a "Q" would be some type of science. Items are shelved alphabetically in Levitt Library by this first row of letters. Alphabet letters " A " through " BX " are shelved on the first floor, and letters " C " through " Z " are shelved on second floor. The first row of the call number may consist of either one, two, or sometimes three letters. They would be shelved as in the following example:
A AB AG AZ BA BC
Second Row -- Whole Numbers
The second row of a call number is made up of numbers. These numbers read as whole numbers and respresent a subdivision of the subject. They affect shelving in the following way:
A 97 A 104 A 275 A 350 A 1007 B 10
Third Row -- Decimal, Letter, Number
The third line in the basic " LC " call number is a decimal, letter, number ".H121". The letter is usually the first letter of the author's last name. However, for some subjects, for example in " P ", language and literature, this letter may be another subdivision to indicate the type of literature. Also, if the item has an editor rather than an author, the first letter of the title may be used. The letters are placed in alphabetical order. The number is called a "cutter number". The numbers are read as a decimal. For example, this third line of the basic call number would be shelved in the following order:
.A27 .A273 .A2759 .A277 . A2778 .A3 .A97 .B15
After the third line you may find another letter, number line on some items. These letters are alphabetical and this number is also read as a decimal. You may also find dates of items or volume numbers (V.1, V.2, etc.). You may find " P.1 " and " P.2 " indicating parts, or " C.1 " and " C.2 " indicating the library has more than one copy of the item.
Other Factors that Affect Shelving
Height of the item
Levitt Library uses the terms QUARTO and FOLIO to designate books over 25 centimeters tall. The term QUARTO or FOLIO will be found above the basic call number on these items. QUARTO is found on the call number of items between 25 and 30 centimeters tall and FOLIO is found on items over 30 centimeters tall. QUARTO items are shelved after the regular sized items with the same LC call number. For example, after the B - BX regular size items you will find the QUARTO B - BX size items. FOLIO size items are on a bottom shelf under the QUARTO items because they are so large.
Other Terms Found Above the Basic Library of Congress Call Number