What is a Controlled Vocabulary?
http://www.boxesandarrows.com/archives/what_is_a_controlled_vocabulary.php

Fast, Karl, Fred Leise and Mike Steckel
Boxes and Arrows
2002

Abstract:

Finding the right words to communicate the message of your website can be one of the most difficult parts of developing it. Our authors guide you through the concepts behind a well-designed controlled vocabulary and discuss the pros and cons of its development.