{block name='form_field_item_checkbox'}
<span class="custom-checkbox">
<label>
<input name="{$field.name}" type="checkbox" value="1" {if $field.value}checked="checked"{/if} {if $field.required}required{/if}>
<span><i class="material-icons rtl-no-flip checkbox-checked"></i></span>
{$field.label nofilter}
</label>
</span>
{/block}
Einfach in {$field.label nofilter} -> {$field.label|unescape:"html" nofilter} hinzufügen.
https://stackoverflow.com/questions/16449583/show-a-smarty-variable-with-html-content