When accessing our electronic catalog at the library or on the web you will notice call numbers assigned to each item in the database. In the library you will also notice most of our shelves contain numbers while others contain letters. These are all examples of call numbers, which help us find where a book is stored in a library.

Most items at Middletown Thrall Library are filed according to the Dewey Decimal System, a system where all human knowledge is broken down into finite numbers; for example, literature may be found in the 800 section, while language books can be found in the 400 section. Some Dewey numbers are short, such as 123 DEF, while others may be longer, such as 123.678 ABC. Reference items (beginning with REF) indicate a book may used at the library but not borrowed.

Audio books (except those interfiled in the 400s Language section) begin with the call letters BOT (unabridged) or AC (abridged).

Biographies are filed alphabetically by the subject's name.

Children's items begin with J, JB, JE, or JP are available in the Children's Department. J stands for "juvenile."

Developmental Disability Materials begin with "DDM" and are available in the Children's Department

Fiction is filed alphabetically by the author's last name.

Government Documents are filed by SuDoc numbers. SUDOC stands for the Superintendent of Documents. The call numbers are filed alphabetically by the government agency they came from, so a document stored in the ED section came from the U.S. Education Department and a document stored under S came from the U.S. State Department.

Large Print materials begin with "LP."

Music collection call numbers work according to ANSCR, or Alpha-Numeric System for Classification of Recordings. There are four parts (called "terms") to an ANSCR number. The first term pertains to the type of music; for example, a CD with opera music's first term will be B while a CD featuring a Broadway songs will likely be filed under K, while represents musicals in ANSCR. The second term pertains to the composer or performer. The third term is based on the album's title, and the fourth term represents the performer's last name, if any. An example of an ANSCR call number is

which applies to the audio CD Mahler: Symphony No. 9, directed by Leonard Bernstein. A chart outlining ANSCR call numbers has been posted by the music collection.

New Materials have call numbers beginning with the words "Express Fiction" in the catalog. These new items are shelved in the New Books section across from the Circulation Desk. There are three sections in this area: Fiction, nonfiction, and biography. Fiction is filed by author's last name, nonfiction by Dewey, and Biography by the subject's last name.

Nonfiction almost always is filed by the Dewey Decimal System.

Parenting Collection call numbers begin with "Parenting Collection."

Videos are filed in four sections:

• Our main collection contains movies filed alphabetically by their title, while nonfiction videos are filed according to the Dewey Decimal System.
• Another special video collection of ours is known as the Cunningham Collection. These items, donated to us, have call numbers beginning with CUN and are stored on the shelves across from our main video collection
• Videos in our Spanish collection begin with "SPANISH" and are kept near our main video collection.
• Children's videos have call numbers beginning with J, JB, JE, and JP, and are stored in the Children's Department.

Young Adult items begin with "YA." Young Adult nonfiction is interfiled with adult nonfiction, whereas YA fiction is maintained separately by the Young Adult Corner.

If you have any trouble locating an item or interpreting a call number please see a librarian or submit your question to us through our online reference service.