How to Interpret a Call Number

Books and journals in Memorial and Science Libraries are arranged by Library of Congress call numbers. MARQCAT, the Libraries' online catalog, provides the library location, call number for all items and, for books, the circulation status. The information appears in a box similar to this:

  LOCATION               CALL NO.                  STATUS
  Science Library        QH 361 .B693 1988         AVAILABLE

" Location" indicates in which library or special collection the item is located, e.g. Science Library or Memorial Browsing Collection. The call number is analogous to a person's address which identifies the state, city, street, and, finally, the individual building, possibly even the apartment where that person lives. Call numbers identify location by discipline, topic, and finally, the individual item. Marquette Libraries use the Library of Congress call number system, employing a combination of letters and numbers in three or more sections: the first section is made up of one or two letters; the second section, one or more numerals; the third and occasionally fourth section, letter/numeral combination; and finally a date may appear.

Example:

Call numbers are arranged on the shelves by each successive section. Some confusion may occur when reading the second and third/fourth section. The numerals in the second section are read as whole numbers unless a decimal point appears within. The numerals within the third/fourth sections are always read as decimal numbers whether a decimal appears before the letter or not. This makes a significant difference in how the call numbers are arranged on the shelf.

Example:

The complexity of the system can easily cause confusion when attempting to locate a single call number in row upon row of books and journals. If a specific call number cannot be located, double check the library location, call number and availability status in MARQCAT, then double check the area in which the call number should be, and if it still cannot be found, consult the staff at the Circulation Desk. For more information on interpreting a call number, ask at the Reference Desk.