The resulting document becomes a single composite XML Information Set. The XInclude mechanism can be used to incorporate content from either XML files or non-XML text files. High Quality Content by WIKIPEDIA articles! The mechanism is similar to HTML' s tag (which is specific to the HTML markup language), but the XInclude mechanism works with any XML format, such as SVG and XHTML. XInclude is a generic mechanism for merging XML documents, by writing inclusion tags in the main document to automatically include other documents or parts thereof.