What are the key considerations when using XSLT to transform HTML content based on specific criteria?

When using XSLT to transform HTML content based on specific criteria, key considerations include identifying the criteria accurately, creating appropriate templates in the XSLT stylesheet to match the criteria, and ensuring the transformation logic is correctly implemented.

// Sample XSLT stylesheet to transform HTML content based on specific criteria
$xsl = new DOMDocument();
$xsl->load('stylesheet.xsl');

// Load the XML content to be transformed
$xml = new DOMDocument();
$xml->load('content.xml');

// Create and configure the XSLT processor
$proc = new XSLTProcessor();
$proc->importStylesheet($xsl);

// Perform the transformation
if ($result = $proc->transformToXML($xml)) {
    echo $result;
} else {
    echo 'Error transforming XML.';
}