The ability to search a document’s metadata is a powerful tool in Acrobat. In order to use the tool, you need to know just a little bit about what metadata is. Adobe Acrobat 5.0 and later contains metadata in XML (eXtensible Markup Language) format. In Acrobat 7 and 8 object metadata are accessible.
The metadata of a file or an image is information related to the document structure, origination, content, interchange, and processing. Metadata might include, for example, the document author’s name, the creation date, modified date, the PDF producer, copyright information on images, color space on images, and more.
When you click Search, the search results report all files where the searched words are contained in a document’s metadata. XMP (eXtensible Metadata Platform) is an XML framework that provides all Adobe programs a common language for communicating standards related to document creation and processing throughout publishing workflows.
XMP is a format, and document metadata viewed in XML source code can be exported to XMP format. Once in XMP, it can be exchanged between documents. To take a look at the XML source code of the XMP metadata for a document, choose File >> Properties and click the Description tab.
In the Description tab click on Additional Metadata to open the dialog box. Click Advanced and expand the listed items by clicking the symbol adjacent to each listed item. At the bottom of the dialog box are buttons used for replacing, appending, saving, and deleting data.
Click Save to export the XMP data that can be shared in workflows across many different file types. For the purposes of searching information, any of the text you see in the source code in the Advanced list can be searched.