DITA 1.1 includes a new element, <data>. This element and the content inside it is ignored in the transformation process of DITA files.
As a DITA content author you can add the <data> element, and put content inside it. When you transform the DITA files to the output that you want, the transformation ignores the <data> element and any content inside it.
If you specialize the <data> element, and put information inside the specialized element, you can create a transform override to use the information.