This page let you test the rendering font-family declaration for monospaced fonts. TODO: add some references here :-)

font-family: monospace;

font-family: "Courier New";

font-family: Courier;

font-family: monospace, monospace;

font-family: monospace, "Courier New";

font-family: monospace, Courier;

font-family: monospace, Verdana;

font-family: monospace, DOESNOTEXISTREALLY;