Extensible Markup Language (XML (Extensible Markup Language (XML): A format for delivering rich, structured data from an application in a standard, consistent way. XML describes the content of a Web document, whereas HTML tags describe how the document looks.)) and Hypertext Markup Language (HTML (HTML: The standard markup language used for documents on the World Wide Web. HTML uses tags to indicate how Web browsers should display page elements such as text and graphics and how to respond to user actions.)) are both designed for web documents. Unlike HTML, XML is designed for data. Also unlike HTML, XML supports the use of customized tags for specific data.
The rules governing the syntax of XML tags are stricter than those for HTML. A missing tag or incorrectly formatted attribute in an XML document renders the file useless.
When you select the Apply XML formatting rules option, Microsoft FrontPage searches the XML code for missing or incomplete tags and applies the correct tags.
Important If you apply XML formatting to a document formatted to exclude selected ending tags (for example, the </P> tag), those tags will likely be applied by this feature.