title: R ellipsis - further arguments passed to or from other methods
body: <p>I understand what dot-dot-dot means in general. I understand how to use it when I want to create my own function with unknown number of parameters.</p>
  
  <p>I do not understand how it works for example at function <code>variable.names()</code>. When I execute <code>?variable.names</code>, there is written the following: </p>
  
  <blockquote>
    <p>...    further arguments passed to or from other methods.</p>
  </blockquote>
  
  <p>What does it really mean? I do not know what I can pass there. How and where will be these passed arguments used.</p>