title: What is the proper declaration of main in C++?
body: <h2>Questions</h2>
  <ul>
  <li><p>What is the proper signature of the <code>main</code> function in C++?</p>
  </li>
  <li><p>What is the correct return type, and what does it mean to return a value from <code>main</code>?</p>
  </li>
  <li><p>What are the allowed parameter types, and what are their meanings?</p>
  </li>
  <li><p>Is this system-specific?</p>
  </li>
  <li><p>Have those rules changed over time?</p>
  </li>
  <li><p>What happens if I violate them?</p>
  </li>
  </ul>