The fallback element appears as a child of an include element. It provides a mechanism for recovering from missing resources.
The fallback element can appear only as a child of an include element.
In the given example an attempt to include include.xml document is being done, and a fallback mechanism is provided that is in its turn tryes to include include.txt document. In case both includes are failed, the text "Both includes are failed" will be inserted into the document tree.<xi:include href="include.xml" xmlns:xi="http://www.w3.org/2001/XInclude"> <xi:fallback> <xi:include href="include.txt" parse="text"> <xi:fallback>Both includes failed</xi:fallback> </xi:include> </xi:fallback> </xi:include>