Margin three
Margin right three
Margin bottom three
Margin horizontal three
Margin vertical three
<div class="m6">Margin three</div>
<div class="mr6">Margin right three</div>
<div class="mb6">Margin bottom three</div>
<div class="mh6">Margin horizontal three</div>
<div class="mv6">Margin vertical three</div>spacing.css, line 228