Where can one find comprehensive XML guidelines for creating Excel documents in PHP?

To create Excel documents in PHP using XML, one can refer to the official Microsoft documentation on the Open XML format for Excel files. This documentation provides comprehensive guidelines on how to structure XML data to generate Excel documents programmatically. By following these guidelines, developers can effectively create Excel files using PHP.

// Sample PHP code snippet for creating an Excel document using XML

$xml = '<?xml version="1.0"?>
<Workbook xmlns="urn:schemas-microsoft-com:office:spreadsheet"
 xmlns:o="urn:schemas-microsoft-com:office:office"
 xmlns:x="urn:schemas-microsoft-com:office:excel"
 xmlns:ss="urn:schemas-microsoft-com:office:spreadsheet"
 xmlns:html="http://www.w3.org/TR/REC-html40">
 <Worksheet ss:Name="Sheet1">
  <Table>
   <Row>
    <Cell><Data ss:Type="String">Hello</Data></Cell>
    <Cell><Data ss:Type="String">World</Data></Cell>
   </Row>
  </Table>
 </Worksheet>
</Workbook>';

header('Content-Type: application/vnd.ms-excel');
header('Content-Disposition: attachment;filename="example.xls"');
echo $xml;