Normal:
<?php
// Open existing index
$index Zend_Search_Lucene::open('/data/my-index');

$doc = new Zend_Search_Lucene_Document();
// Store document URL to identify it in search result.
$doc->addField(Zend_Search_Lucene_Field::Text('url'$docUrl));
// Index document content
$doc->addField(Zend_Search_Lucene_Field::UnStored('contents'$docContent));

// Add document to the index.
$index->addDocument($doc);
?>

HTML document:
<?php
$doc 
Zend_Search_Lucene_Document_Html::loadHTMLFile($filename);
$index->addDocument($doc);
?>