title: One class per file rule in .NET?
body: <p>I follow this rule but some of my colleagues disagree with it and argue that if a class is smaller it can be left in the same file with other class(es).</p>
  
  <p>Another argument I hear all the time is "Even Microsoft doesn't do this, so why should we?"</p>
  
  <p>What's the general consensus on this? Are there cases where this should be avoided?</p>