Another aspect of document design is including elements that are relevant to different contexts and coding the document to allow elements to display or not, as appropriate. For example, although they are fundamental to any screen design, navigation links are not helpful when printed on paper. With a document coded for selective display, you can use css in the print style sheet to hide navigation links in printed versions of the page. And while we tend to focus on document design for the computer screen, and most of our document content addresses the needs of visual browsing, some elements are helpful in other contexts.