title: Pandas Excel file parse arguments
body: <p>I have some legacy code, that uses parameter '16' in 'pandas.ExcelFile.parse' function:</p>
  
  <pre><code>xls_file = pd.ExcelFile(xls_file_path) 
  df = xls_file.parse('16')
  </code></pre>
  
  <p>Using the above or just this:</p>
  
  <pre><code>df = xls_file.parse()
  </code></pre>
  
  <p>returns similar dataframes with all the columns from Excel file. The only difference is that in the last case dataframe has more records then in the first case.</p>
  
  <p>What does "parse('16')" mean? Can not deduce this from pandas docs.</p>