title: How to change the font of the main title in plot()
body: <p>From <a href="http://www.harding.edu/fmccown/R/" rel="noreferrer">this page</a> I have come to understand that:</p>
  
  <pre><code>font.main=4
  </code></pre>
  
  <p>will give me a italic bold title for my figure. However I want neither but a plain-old-sans-serif font. More generally I have been looking for a table of what values does what but not found any so far. Is there one and if so where can I see it?</p>