<!DOCTYPE HTML>
<html>
<head><meta charset="utf-8"/></head>
<body>
<p>The first grapheme cluster here contains three code points: two characters (Lo unicode category) which join up to be drawn with a single glyph, and a third code point which is a nonspacing mark (Mn unicode category), which is drawn as a second glyph on top of the first glyph, using a negative advance. This run has an initial advance.</p>
<div dir="RTL">
<span style="font-size: 100pt; background: blue;">&#1604;&#1575;&#1611; &#1609; z</span></body>
</div>
</html>