Entity Reference: Second Use

• To cause a large substitution to be made within a document
• The DTD specifies the text to be substituted

  <exam>
  <qapair>
    &question1;
    <answer>George VI</answer>
  </qapair>
  <qapair>
    &question2;
    <answer>Two</answer>
  </qapair>
  </exam>