{% with post.tags.all as tags %}
{% if tags %}
    <span class='post-tag-list'>filed under: 
        {% for tag in tags %}
            <a href='{% url blogs.tagged_posts tag.name %}'>{{ tag.name }}</a>{% if not forloop.last %},{% endif %}
        {% endfor %}
    </span>
{% endif %}
{% endwith %}

{% with post.tags.all as tags %}
{% if tags or post.in_reply_to.campaign %}
    <span class='post-tag-list'>filed under: 
        {% for tag in tags %}
        <a href='{% url blogs.tagged_posts tag.name %}'>{{ tag.name }}</a>{% if not forloop.last %},{% endif %}{% endfor %}{% if post.in_reply_to.campaign %}{% if tags %}, {% endif %}
            <a href='{% url blogs.show_campaign %}'>{{ post.in_reply_to.campaign.title }}</a>
        {% endif %}
    </span>
{% endif %}
{% endwith %}

Add 'filed under' for campaigns
Add 'filed under' for campaigns
