Library of Congress Subject Headings

The Library of Congress Subject Headings are a massive controlled vocabulary list used by the majority of libraries. It is currently published in 5 large, red volumes.

Work on creating LCSH list was started in 1898, with the first edition being published in 1909.  The newest edition (27th) was published in June, 2004.
It has over 270,000 usable headings, and over 490,000 headings that are used for cross referencing. It had 7,200 new terms added to the lists.

The J.D. Williams library owns the following copies:

Call Number
10th ed. - 1986 Main
Z695 .L695 1986 
12th ed. - 1989
Z695 .L695 1989
15th ed. - 1992 Main
Z695 .L695 1992
11th ed. - 26th ed.
Gov't Documents LC 26.7: 
1992-2002, microfiche Gov't Documents LC 26.7/2:

Definition of Subject Headings
Library of Congress Subject Headings
Types of Subject Headings
Types of Subdivisions
Example LCSH Entry