diff --git a/boards/forms.py b/boards/forms.py
--- a/boards/forms.py
+++ b/boards/forms.py
@@ -332,7 +332,7 @@ class ThreadForm(PostForm):
             # If this is a new tag, don't check for its parents because nobody
             # added them yet
             if not created:
-                tag_set |= tag.get_all_parents()
+                tag_set |= set(tag.get_all_parents())
 
         for tag in tag_set:
             if tag.required:
@@ -340,7 +340,6 @@ class ThreadForm(PostForm):
                 break
 
         if not required_tag_exists:
-            all_tags = Tag.objects.filter(required=True)
             raise forms.ValidationError(
                 _('Need at least one section.'))
 
diff --git a/boards/models/tag.py b/boards/models/tag.py
--- a/boards/models/tag.py
+++ b/boards/models/tag.py
@@ -122,11 +122,11 @@ class Tag(models.Model, Viewable):
         return self.parent
 
     def get_all_parents(self):
-        parents = set()
+        parents = list()
         parent = self.get_parent()
         if parent and parent not in parents:
-            parents.add(parent)
-            parents |= parent.get_all_parents()
+            parents.insert(0, parent)
+            parents = parent.get_all_parents() + parents
 
         return parents
 
diff --git a/boards/templates/boards/all_threads.html b/boards/templates/boards/all_threads.html
--- a/boards/templates/boards/all_threads.html
+++ b/boards/templates/boards/all_threads.html
@@ -73,11 +73,11 @@
                 <p>{{ tag.get_description|safe }}</p>
             {% endif %}
             <p>{% blocktrans with active_thread_count=tag.get_active_thread_count thread_count=tag.get_thread_count post_count=tag.get_post_count %}This tag has {{ thread_count }} threads ({{ active_thread_count}} active) and {{ post_count }} posts.{% endblocktrans %}</p>
-            {% if tag.get_parent %}
+            {% if tag.get_all_parents %}
                 <p>
-                    {% if tag.get_parent %}
-                        {{ tag.get_parent.get_view|safe }} /
-                    {% endif %}
+                    {% for parent in tag.get_all_parents %}
+                        {{ parent.get_view|safe }} &gt;
+                    {% endfor %}
                     {{ tag.get_view|safe }}
                 </p>
             {% endif %}