<svg width="300" height="200"
xmlns="http://www.w3.org/2000/svg"
xmlns:html="http://www.w3.org/1999/xhtml">
<title>Rectangle coordinates and sizes specified by percentage</title>
<html:link rel="help" href="https://svgwg.org/svg2-draft/geometry.html"/>
<html:link rel="match" href="rect-ref.svg" />
<style>
rect {
x: 10%;
y: 30%;
width: 40%;
height: 50%;
fill: blue;
}
</style>
<rect />
</svg>