Books 

The Schlesinger Library uses the Dewey Decimal call number system, which is divided into 10 main sections: 

• 000 – Computer science, information & general works  

• 100 – Philosophy and psychology  

• 200 – Religion  

• 300 – Social sciences  

• 400 – Language  

• 500 – Science (including mathematics)  

• 600 – Technology  

• 700 – Arts and recreation  

• 800 – Literature  

• 900 – History, geography, and biography  

A typical number is 641.66 A283c, which is the call number of The Classic Cooking of Spain, by Jeannette Aquilar. The first three numbers put it into the technology area. As can be inferred by the name Dewey Decimal, the second part of the number is a decimal, which means that 641.645 comes before 641.66. The first letter, always a capital letter, generally refers to the first letter of the author’s last name. The digits following the capital letter are calculated so that the authors within that subject fall in alphabetical order. The last letter(s) generally refers to the first word of the title of the book.  

Periodicals 

Periodicals do not have call numbers. HOLLIS will indicate if the periodical is housed onsite or is at the Harvard Depository.

There will, of course be exceptions! If you can’t find something, ask your supervisor or one of your colleagues in the Research Services Department. 

Manuscript materials  

Some manuscript collections have been processed; some have not. The Schlesinger Library makes unprocessed collections available for research whenever possible. 

Processed Collections

If a collection has been processed, it will have a call number.  

Currently, the Library assigns and MC number to a collection when it is processed:

MC 432 = Manuscript Collection + a number which indicates the order in which it was added to the item. Ex. MC 432 was processed before MC 433.

Previously, the Library used a few other other call number designations:

A-47 = The letter A was assigned to collections about individuals.

B-28 = The letter B was assigned to collections about businesses, organizations, or other groups.

WRC = Woman's Rights Collection, the Library's flagship collection donated by Maud Wood Park in 1943.

178  = An early designation where the number simply indicates the order in which the collection was processed. Ex 178 was processed before 179.

Examples of call numbers for smaller collections: 

A/D238 = A "small A" folder. Usually represents one folder of material, but may represent a range of folders. The letter A is assigned to collections about individuals.

B/R67 = A "small B" folder. Usually represents one folder of material, but may represent a range of folders. The letter B was assigned to collections about businesses, organizations, or other groups.

Unprocessed Collections

If a collection is unprocessed, it will have an accession number.  

Examples of accession numbers include the following: 

94-M132 = This notation indicates the collection was the 132nd accession in the year 1994.

71-M149—82-M12 = This notation indicates a collection containing multiple accessions. The first accession in the collection was the 149th accession in 1971, and the last accession in the collection was the 12th accession in 1982. While this indicates a minimum of two accessions, additional accessions may have been received and represented by the "–". A researcher will not be able to tell exactly how many accessions were made just by looking at this accession range. To find that out, they will need to Ask a Librarian!

Radcliffe College Archive

Below are some of the call numbers used for Radcliffe College Archive Collections:

SC (#) = Special Collection; refers to collections, usually of individual Radcliffe Alumnae, that are part of the Radcliffe College Archives. 

RG (Roman Numeral) = Record Group; refers to Radcliffe College Archives institutional records

RA.A/26 = A Radcliffe College Archive "small A" folder.  The letter A is assigned to collections about individuals.

Audiovisual Collections

PC-1, PC-2, etc., = entirely photographs. 

Mp-1, Mp-2, etc., = motion pictures. Consult the Audiovisual Librarian. 

CD-34, CD-81, etc., = CDs (compact discs) and DVDs.  

T-1, T-2, etc., = audiotapes.  

Vt-1, Vt-2, etc., = videotapes.  

Phon-1, Phon-2, etc. = phonograph records.

Other Call Numbers

OH-1, OH-2, etc., = oral histories. 

E-1, E-12, etc., = born digital materials. Consult with the Head of Digital Collections for assistance if links to the items are not available in the finding aid.

Rarely Used Call Numbers

D-1, D-2, etc., = collections given to us on deposit. 

WTBD = Work To Be Done. Check with your supervisor before paging any items with a WTBD call number for use in the Reading Room.