First, deal with a couple of the most common symptoms you are likely to encounter when you first try to code SVG by hand. The first symptom is when nothing is displayed. The second is that only some of the parts of the image are displayed.
Getting into this position is easy. Even minor syntax errors can cause an SVG document or element to fail to be displayed.
For example, if you make a simple mistake, like omitting a closing quotation mark in the following simple SVG, which ought to display a simple rectangle with a blue outline, the browser window is blank as in Figure 14.01.