Ponysearch/searx/templates/oscar/categories.html

<div id="categories">
{% if rtl %}
    {% for category in categories | reverse %}
        <input class="hidden" type="checkbox" id="checkbox_{{ category|replace(' ', '_') }}" name="category_{{ category }}" {% if category in selected_categories %}checked="checked"{% endif %} />
        <label class="input-group-addon" for="checkbox_{{ category|replace(' ', '_') }}">{{ _(category) }}</label>
        </label>
    {% endfor %}
{% else %}
    {% for category in categories %}
        <input class="hidden" type="checkbox" id="checkbox_{{ category|replace(' ', '_') }}" name="category_{{ category }}" {% if category in selected_categories %}checked="checked"{% endif %} />
        <label class="input-group-addon" for="checkbox_{{ category|replace(' ', '_') }}">{{ _(category) }}</label>
    {% endfor %}
{% endif %}
</div>