Example
Markup
<label class="specialradiobox" for="specialradioboxradio1">
<input type='radio' name='specialradiobox' id='specialradioboxradio1' value='' aria-label="Radio 1">
<i></i>
<span aria-hidden="true">Radio 1</span>
</label>
<label class="specialradiobox" for="specialradioboxradio2">
<input type='radio' name='specialradiobox' id='specialradioboxradio2' value='' aria-label="Radio 2">
<i></span>
<span aria-hidden="true">Radio 2</span>
</label>
Source:
build/doc/doc.css, line 4105