&gt;x&lt;/p&gt;
  &lt;p class="reference"&gt;x&lt;/p&gt;
&lt;/div&gt;</code></pre>
<figcaption>The test code might look like this: it assumes that a black square glyph maps to <code>x</code> and the "Heavy H" glyph maps to <code>H</code></figcaption>
</figure>
</section>

<section>
<h3>TBD</h3>
<p>In <a href="https://drafts.csswg.org/css-writing-modes/#text-combine-layout">9.1.2 Layout Rules</a> the spec says:
<blockquote>
The UA should center the glyphs horizontally and vertically within the measured 1em s