Include-source

The   property is used in CSS. This property inserts another document into the current document, replacing the current element's content. Any elements or CSS properties applied to or inherited by the current element are applied to the inserted content as well. This property is similar to the HTML  element in that they both insert another document and its contents into the current document.

Values
Example:

body { position: absolute; top: 100px; left: 300px; width: 200px; height: 200px; border: thin solid black; include-source: url("http://www.example.com/testpage.html"); }