in the work. Other kinds of floating blocks may be differentiated as well, for example: Sidebar: For digressions from the main narrative. For example, a technical manual on the usage of a product might include examples of how various people have employed the product in their work in sidebars. Also called an intermezzo. See sidebar (publishing). Program: Articles and books on computer programming often place code and algorithms in a figure. Equation: Writing on mathematics may place large blocks of mathematical notation in numbered blocks set apart from the main text. Presenting layouts under development A mockup of a layout might be created to get early feedback, usually before all the content is actually ready. Whether for paper or electronic media, the first draft of a layout might be simply a rough paper and pencil sketch. A comprehensive layout for a new magazine might show placeholders for text and images, but demonstrate placement, typographic style, and other idioms intended to set the pattern for actual issues or a particular unfinished issue. A website wireframe is a low-cost way to show layout without doing all the work of creating the final HTML and CSS, and without writing the copy or creating any images. Lorem ipsum text is often used to avoid the embarrassment any improvised sample copy might cause if accidentally published. Likewise, placeholder images are often labeled "for position only". See also Aesthetics Book design Canons of page construction Database publishing Desktop publishing Editing Layout engine News design Page layout Publishing Interchange Language Slicing Web design References External links SGML page at www.xml.org Symbols – All articles categorized as relating to typographical symbols TeX Users Group XML page at www.W3C.org Book arts Communication design Graphic design Composition in visual art