title: Why may not the colspan attribute be set to zero?
body: <p>According to the <code>HTML5</code> description the attribute <code>rowspan</code> may have value 0. In this case the value zero means that the cell is to span all remaining cells of the given column in the row group.</p>
  
  <p>However the value of <code>colspan</code> may not be equal to zero.</p>
  
  <p>So a question arises what is the reason for such a restriction for the attribute <code>colspan</code>?</p>