--- a/ckanext/example/forms.py
+++ b/ckanext/example/forms.py
@@ -1,9 +1,8 @@
 import os, logging
 from ckan.authz import Authorizer
 from ckan.logic.converters import convert_to_extras,\
-    convert_from_extras, convert_to_tags, convert_from_tags
+    convert_from_extras, convert_to_tags, convert_from_tags, free_tags_only
 from ckan.logic.schema import package_form_schema, group_form_schema
-from ckan.model import vocabulary
 from ckan.lib.base import c, model
 from ckan.plugins import IDatasetForm, IGroupForm, IConfigurer, IConfigurable
 from ckan.plugins import implements, SingletonPlugin
@@ -209,7 +208,7 @@
         schema = package_form_schema()
         schema.update({
             'tags': {
-                '__extras': [keep_extras]
+                '__extras': [keep_extras, free_tags_only]
             },
             'vocab_tag_string': [convert_from_tags(self.vocab_name), ignore_missing],
             'published_by': [convert_from_extras, ignore_missing],

--- a/ckanext/example/theme/templates/forms/dataset_form.html
+++ b/ckanext/example/theme/templates/forms/dataset_form.html
@@ -137,7 +137,7 @@
     <dt class="tags-label"><label class="field_opt" for="tags">Tags</label></dt>
     <dd class="tags-field">
       <input class="long autocomplete-tag" id="tag_string" name="tag_string" size="60" type="text" 
-               value="${data.get('tag_string') or ', '.join([tag['name'] for tag in data.get('tags', [])])}" />
+               value="${data.get('tag_string') or ', '.join([tag['name'] for tag in data.get('tags', []) if not tag.get('vocabulary_id')])}" />
     </dd>
     <dd class="tags-instructions instructions basic" i18n:msg="">Comma-separated terms that may link this dataset to similar ones. For more information on conventions, see <a href="http://wiki.okfn.org/ckan/doc/faq#TagConventions">this wiki page</a>.</dd>
     <dd class="tags-instructions hints">e.g. pollution, rivers, water quality</dd>