From html you can also declare a default file to be included if the file does not exist
<xt:include default="/manual/files/default" file="/manual/files/no_such_file" />This is the default include file
You can also do a random include of text or html files
Again Only the content between the <body>...</body> tags is included from html files
<xt:include file="/manual/files/random/*" />This is a random file include
