Technical Writing Rules You Didn't Learn in RHET 101
http://www.physics.uiuc.edu/Education/398ST/Fall01/TechRules.pdf

Elliott, Celia M.
University of Illinois

Abstract:

To hyphenate or not to hyphenate, that is the question. As compound nouns evolve over time in Eng- lish, they gradually move from being written 'open' (data base) to being hyphenated (data-base) to being written 'closed' (database). Just where your particular word might be in its evolution is often un- clear and subject to the inscrutable and highly individual logic of copy editors. Consult a recent edition of a standard dictionary.