Gazelle/templates/user/edit-secondary-class.twig

<tr>
    <td class="label">Secondary classes:</td>
    <td>
{% for p in permission %}
        <input type="checkbox" id="perm_{{ p.permId }}" name="secondary_classes[]" value="{{ p.permId }}"{{ p.isSet|checked }}
            />&nbsp;<label for="perm_{{ p.permId }}" style="margin-right: 10px;">{{ p.permName }}</label>
{{ cycle(['', '', '<br />' ], loop.index0) | raw }}
{% endfor %}
    </td>
</tr>