Content and Rendering
When writing documentation to be displayed on assorted media or processed by different technologies, keep the written content and rendering information separate. Many writers use formatting to distinguish between different types of information, such as bold text to add emphasis to important words. With modern technologies, however, writers can use specialized markup to identify important words. This markup allows the text to be rendered according to rules defined for the target medium or technology. Markup also allows information about that text to be retained even when special formatting is not available.