diff --git a/src/main/java/org/gcube/portlets/widgets/ckandatapublisherwidget/client/CKanMetadataPublisher.java b/src/main/java/org/gcube/portlets/widgets/ckandatapublisherwidget/client/CKanMetadataPublisher.java
index 95942e5..f0a3493 100644
--- a/src/main/java/org/gcube/portlets/widgets/ckandatapublisherwidget/client/CKanMetadataPublisher.java
+++ b/src/main/java/org/gcube/portlets/widgets/ckandatapublisherwidget/client/CKanMetadataPublisher.java
@@ -3,9 +3,9 @@ package org.gcube.portlets.widgets.ckandatapublisherwidget.client;
 import java.util.ArrayList;
 import java.util.List;
 
-import org.gcube.portlets.widgets.ckandatapublisherwidget.client.ui.CreateDatasetForm;
-import org.gcube.portlets.widgets.ckandatapublisherwidget.client.ui.MetaDataFieldSkeleton;
 import org.gcube.portlets.widgets.ckandatapublisherwidget.client.ui.TwinColumnSelection.TwinColumnSelectionMainPanel;
+import org.gcube.portlets.widgets.ckandatapublisherwidget.client.ui.form.CreateDatasetForm;
+import org.gcube.portlets.widgets.ckandatapublisherwidget.client.ui.metadata.MetaDataFieldSkeleton;
 import org.gcube.portlets.widgets.ckandatapublisherwidget.shared.ResourceElementBean;
 import org.gcube.portlets.widgets.ckandatapublisherwidget.shared.metadata.MetadataFieldWrapper;
 
@@ -227,10 +227,11 @@ public class CKanMetadataPublisher implements EntryPoint {
 	}
 	
 	// test resources
-	TwinColumnSelectionMainPanel resourcesTwinPanel;
-
+	@SuppressWarnings("unused")
 	private void startTwinColumn() {
 		
+		TwinColumnSelectionMainPanel resourcesTwinPanel;
+		
 		Modal m = new Modal();
 		m.setTitle("Title ......");
 		m.setWidth("1200px");
diff --git a/src/main/java/org/gcube/portlets/widgets/ckandatapublisherwidget/client/CKanPublisherServiceAsync.java b/src/main/java/org/gcube/portlets/widgets/ckandatapublisherwidget/client/CKanPublisherServiceAsync.java
index 5c576ac..29bce2b 100644
--- a/src/main/java/org/gcube/portlets/widgets/ckandatapublisherwidget/client/CKanPublisherServiceAsync.java
+++ b/src/main/java/org/gcube/portlets/widgets/ckandatapublisherwidget/client/CKanPublisherServiceAsync.java
@@ -91,8 +91,18 @@ public interface CKanPublisherServiceAsync {
 	void isPublisherUser(boolean isWorkspaceRequest,
 			AsyncCallback<Boolean> callback);
 
+	/**
+	 * Get the list of vocabulary tags for this scope
+	 * @param orgName
+	 * @return
+	 */
 	void getTagsForOrganization(String orgName,
 			AsyncCallback<List<String>> callback);
 
+	/**
+	 * Validate a geo json field
+	 * @param json
+	 * @return
+	 */
 	void isGeoJSONValid(String json, AsyncCallback<Boolean> callback);
 }
diff --git a/src/main/java/org/gcube/portlets/widgets/ckandatapublisherwidget/client/events/DeleteCustomFieldEvent.java b/src/main/java/org/gcube/portlets/widgets/ckandatapublisherwidget/client/events/DeleteCustomFieldEvent.java
index bf9287d..1111dbc 100644
--- a/src/main/java/org/gcube/portlets/widgets/ckandatapublisherwidget/client/events/DeleteCustomFieldEvent.java
+++ b/src/main/java/org/gcube/portlets/widgets/ckandatapublisherwidget/client/events/DeleteCustomFieldEvent.java
@@ -1,5 +1,5 @@
 package org.gcube.portlets.widgets.ckandatapublisherwidget.client.events;
-import org.gcube.portlets.widgets.ckandatapublisherwidget.client.ui.CustomFieldEntry;
+import org.gcube.portlets.widgets.ckandatapublisherwidget.client.ui.metadata.CustomFieldEntry;
 
 import com.google.gwt.event.shared.GwtEvent;
 
diff --git a/src/main/java/org/gcube/portlets/widgets/ckandatapublisherwidget/client/ui/CreateDatasetForm.java b/src/main/java/org/gcube/portlets/widgets/ckandatapublisherwidget/client/ui/form/CreateDatasetForm.java
similarity index 99%
rename from src/main/java/org/gcube/portlets/widgets/ckandatapublisherwidget/client/ui/CreateDatasetForm.java
rename to src/main/java/org/gcube/portlets/widgets/ckandatapublisherwidget/client/ui/form/CreateDatasetForm.java
index 16a29bd..22fd71e 100644
--- a/src/main/java/org/gcube/portlets/widgets/ckandatapublisherwidget/client/ui/CreateDatasetForm.java
+++ b/src/main/java/org/gcube/portlets/widgets/ckandatapublisherwidget/client/ui/form/CreateDatasetForm.java
@@ -1,4 +1,4 @@
-package org.gcube.portlets.widgets.ckandatapublisherwidget.client.ui;
+package org.gcube.portlets.widgets.ckandatapublisherwidget.client.ui.form;
 
 import java.util.ArrayList;
 import java.util.HashMap;
@@ -14,10 +14,13 @@ import org.gcube.portlets.widgets.ckandatapublisherwidget.client.events.CloseCre
 import org.gcube.portlets.widgets.ckandatapublisherwidget.client.events.DeleteCustomFieldEvent;
 import org.gcube.portlets.widgets.ckandatapublisherwidget.client.events.DeleteCustomFieldEventHandler;
 import org.gcube.portlets.widgets.ckandatapublisherwidget.client.ui.TwinColumnSelection.TwinColumnSelectionMainPanel;
-import org.gcube.portlets.widgets.ckandatapublisherwidget.client.ui.dataset.resources.AddResourceContainer;
-import org.gcube.portlets.widgets.ckandatapublisherwidget.client.ui.dataset.resources.AddResourceToDataset;
-import org.gcube.portlets.widgets.ckandatapublisherwidget.client.ui.dataset.resources.AddedResourcesSummary;
-import org.gcube.portlets.widgets.ckandatapublisherwidget.client.ui.dataset.resources.TagsPanel;
+import org.gcube.portlets.widgets.ckandatapublisherwidget.client.ui.metadata.CategoryPanel;
+import org.gcube.portlets.widgets.ckandatapublisherwidget.client.ui.metadata.CustomFieldEntry;
+import org.gcube.portlets.widgets.ckandatapublisherwidget.client.ui.metadata.MetaDataFieldSkeleton;
+import org.gcube.portlets.widgets.ckandatapublisherwidget.client.ui.resources.AddResourceContainer;
+import org.gcube.portlets.widgets.ckandatapublisherwidget.client.ui.resources.AddResourceToDataset;
+import org.gcube.portlets.widgets.ckandatapublisherwidget.client.ui.resources.AddedResourcesSummary;
+import org.gcube.portlets.widgets.ckandatapublisherwidget.client.ui.tags.TagsPanel;
 import org.gcube.portlets.widgets.ckandatapublisherwidget.client.ui.utils.InfoIconsLabels;
 import org.gcube.portlets.widgets.ckandatapublisherwidget.shared.DatasetBean;
 import org.gcube.portlets.widgets.ckandatapublisherwidget.shared.OrganizationBean;
diff --git a/src/main/java/org/gcube/portlets/widgets/ckandatapublisherwidget/client/ui/CreateDatasetForm.ui.xml b/src/main/java/org/gcube/portlets/widgets/ckandatapublisherwidget/client/ui/form/CreateDatasetForm.ui.xml
similarity index 99%
rename from src/main/java/org/gcube/portlets/widgets/ckandatapublisherwidget/client/ui/CreateDatasetForm.ui.xml
rename to src/main/java/org/gcube/portlets/widgets/ckandatapublisherwidget/client/ui/form/CreateDatasetForm.ui.xml
index fc82563..22a017f 100644
--- a/src/main/java/org/gcube/portlets/widgets/ckandatapublisherwidget/client/ui/CreateDatasetForm.ui.xml
+++ b/src/main/java/org/gcube/portlets/widgets/ckandatapublisherwidget/client/ui/form/CreateDatasetForm.ui.xml
@@ -1,7 +1,7 @@
 <!DOCTYPE ui:UiBinder SYSTEM "http://dl.google.com/gwt/DTD/xhtml.ent">
 <ui:UiBinder xmlns:ui="urn:ui:com.google.gwt.uibinder"
 	xmlns:g="urn:import:com.google.gwt.user.client.ui" xmlns:b="urn:import:com.github.gwtbootstrap.client.ui"
-	xmlns:m="urn:import:org.gcube.portlets.widgets.ckandatapublisherwidget.client.ui.dataset.resources">
+	xmlns:m="urn:import:org.gcube.portlets.widgets.ckandatapublisherwidget.client.ui.tags">
 	<ui:style>
 	.form-main-style {
 		margin-left: 10px;
diff --git a/src/main/java/org/gcube/portlets/widgets/ckandatapublisherwidget/client/ui/CategoryPanel.java b/src/main/java/org/gcube/portlets/widgets/ckandatapublisherwidget/client/ui/metadata/CategoryPanel.java
similarity index 99%
rename from src/main/java/org/gcube/portlets/widgets/ckandatapublisherwidget/client/ui/CategoryPanel.java
rename to src/main/java/org/gcube/portlets/widgets/ckandatapublisherwidget/client/ui/metadata/CategoryPanel.java
index 8351e03..3552e69 100644
--- a/src/main/java/org/gcube/portlets/widgets/ckandatapublisherwidget/client/ui/CategoryPanel.java
+++ b/src/main/java/org/gcube/portlets/widgets/ckandatapublisherwidget/client/ui/metadata/CategoryPanel.java
@@ -1,4 +1,4 @@
-package org.gcube.portlets.widgets.ckandatapublisherwidget.client.ui;
+package org.gcube.portlets.widgets.ckandatapublisherwidget.client.ui.metadata;
 
 import java.util.ArrayList;
 import java.util.List;
diff --git a/src/main/java/org/gcube/portlets/widgets/ckandatapublisherwidget/client/ui/CategoryPanel.ui.xml b/src/main/java/org/gcube/portlets/widgets/ckandatapublisherwidget/client/ui/metadata/CategoryPanel.ui.xml
similarity index 100%
rename from src/main/java/org/gcube/portlets/widgets/ckandatapublisherwidget/client/ui/CategoryPanel.ui.xml
rename to src/main/java/org/gcube/portlets/widgets/ckandatapublisherwidget/client/ui/metadata/CategoryPanel.ui.xml
diff --git a/src/main/java/org/gcube/portlets/widgets/ckandatapublisherwidget/client/ui/CustomFieldEntry.java b/src/main/java/org/gcube/portlets/widgets/ckandatapublisherwidget/client/ui/metadata/CustomFieldEntry.java
similarity index 99%
rename from src/main/java/org/gcube/portlets/widgets/ckandatapublisherwidget/client/ui/CustomFieldEntry.java
rename to src/main/java/org/gcube/portlets/widgets/ckandatapublisherwidget/client/ui/metadata/CustomFieldEntry.java
index 45a7ff1..ff7cf00 100644
--- a/src/main/java/org/gcube/portlets/widgets/ckandatapublisherwidget/client/ui/CustomFieldEntry.java
+++ b/src/main/java/org/gcube/portlets/widgets/ckandatapublisherwidget/client/ui/metadata/CustomFieldEntry.java
@@ -1,4 +1,4 @@
-package org.gcube.portlets.widgets.ckandatapublisherwidget.client.ui;
+package org.gcube.portlets.widgets.ckandatapublisherwidget.client.ui.metadata;
 
 import org.gcube.portlets.widgets.ckandatapublisherwidget.client.events.DeleteCustomFieldEvent;
 
diff --git a/src/main/java/org/gcube/portlets/widgets/ckandatapublisherwidget/client/ui/CustomFieldEntry.ui.xml b/src/main/java/org/gcube/portlets/widgets/ckandatapublisherwidget/client/ui/metadata/CustomFieldEntry.ui.xml
similarity index 100%
rename from src/main/java/org/gcube/portlets/widgets/ckandatapublisherwidget/client/ui/CustomFieldEntry.ui.xml
rename to src/main/java/org/gcube/portlets/widgets/ckandatapublisherwidget/client/ui/metadata/CustomFieldEntry.ui.xml
diff --git a/src/main/java/org/gcube/portlets/widgets/ckandatapublisherwidget/client/ui/MetaDataFieldSkeleton.java b/src/main/java/org/gcube/portlets/widgets/ckandatapublisherwidget/client/ui/metadata/MetaDataFieldSkeleton.java
similarity index 99%
rename from src/main/java/org/gcube/portlets/widgets/ckandatapublisherwidget/client/ui/MetaDataFieldSkeleton.java
rename to src/main/java/org/gcube/portlets/widgets/ckandatapublisherwidget/client/ui/metadata/MetaDataFieldSkeleton.java
index cffd397..fafadbc 100644
--- a/src/main/java/org/gcube/portlets/widgets/ckandatapublisherwidget/client/ui/MetaDataFieldSkeleton.java
+++ b/src/main/java/org/gcube/portlets/widgets/ckandatapublisherwidget/client/ui/metadata/MetaDataFieldSkeleton.java
@@ -1,4 +1,4 @@
-package org.gcube.portlets.widgets.ckandatapublisherwidget.client.ui;
+package org.gcube.portlets.widgets.ckandatapublisherwidget.client.ui.metadata;
 
 import java.util.ArrayList;
 import java.util.List;
diff --git a/src/main/java/org/gcube/portlets/widgets/ckandatapublisherwidget/client/ui/MetaDataFieldSkeleton.ui.xml b/src/main/java/org/gcube/portlets/widgets/ckandatapublisherwidget/client/ui/metadata/MetaDataFieldSkeleton.ui.xml
similarity index 100%
rename from src/main/java/org/gcube/portlets/widgets/ckandatapublisherwidget/client/ui/MetaDataFieldSkeleton.ui.xml
rename to src/main/java/org/gcube/portlets/widgets/ckandatapublisherwidget/client/ui/metadata/MetaDataFieldSkeleton.ui.xml
diff --git a/src/main/java/org/gcube/portlets/widgets/ckandatapublisherwidget/client/ui/dataset/resources/AddResourceContainer.java b/src/main/java/org/gcube/portlets/widgets/ckandatapublisherwidget/client/ui/resources/AddResourceContainer.java
similarity index 97%
rename from src/main/java/org/gcube/portlets/widgets/ckandatapublisherwidget/client/ui/dataset/resources/AddResourceContainer.java
rename to src/main/java/org/gcube/portlets/widgets/ckandatapublisherwidget/client/ui/resources/AddResourceContainer.java
index 8ab89a5..a5a72f2 100644
--- a/src/main/java/org/gcube/portlets/widgets/ckandatapublisherwidget/client/ui/dataset/resources/AddResourceContainer.java
+++ b/src/main/java/org/gcube/portlets/widgets/ckandatapublisherwidget/client/ui/resources/AddResourceContainer.java
@@ -1,4 +1,4 @@
-package org.gcube.portlets.widgets.ckandatapublisherwidget.client.ui.dataset.resources;
+package org.gcube.portlets.widgets.ckandatapublisherwidget.client.ui.resources;
 
 import com.github.gwtbootstrap.client.ui.TabPanel;
 import com.google.gwt.core.client.GWT;
diff --git a/src/main/java/org/gcube/portlets/widgets/ckandatapublisherwidget/client/ui/dataset/resources/AddResourceContainer.ui.xml b/src/main/java/org/gcube/portlets/widgets/ckandatapublisherwidget/client/ui/resources/AddResourceContainer.ui.xml
similarity index 100%
rename from src/main/java/org/gcube/portlets/widgets/ckandatapublisherwidget/client/ui/dataset/resources/AddResourceContainer.ui.xml
rename to src/main/java/org/gcube/portlets/widgets/ckandatapublisherwidget/client/ui/resources/AddResourceContainer.ui.xml
diff --git a/src/main/java/org/gcube/portlets/widgets/ckandatapublisherwidget/client/ui/dataset/resources/AddResourceToDataset.java b/src/main/java/org/gcube/portlets/widgets/ckandatapublisherwidget/client/ui/resources/AddResourceToDataset.java
similarity index 99%
rename from src/main/java/org/gcube/portlets/widgets/ckandatapublisherwidget/client/ui/dataset/resources/AddResourceToDataset.java
rename to src/main/java/org/gcube/portlets/widgets/ckandatapublisherwidget/client/ui/resources/AddResourceToDataset.java
index 20f4fd9..5347002 100644
--- a/src/main/java/org/gcube/portlets/widgets/ckandatapublisherwidget/client/ui/dataset/resources/AddResourceToDataset.java
+++ b/src/main/java/org/gcube/portlets/widgets/ckandatapublisherwidget/client/ui/resources/AddResourceToDataset.java
@@ -1,4 +1,4 @@
-package org.gcube.portlets.widgets.ckandatapublisherwidget.client.ui.dataset.resources;
+package org.gcube.portlets.widgets.ckandatapublisherwidget.client.ui.resources;
 
 import org.gcube.portlets.widgets.ckandatapublisherwidget.client.CKanPublisherService;
 import org.gcube.portlets.widgets.ckandatapublisherwidget.client.CKanPublisherServiceAsync;
diff --git a/src/main/java/org/gcube/portlets/widgets/ckandatapublisherwidget/client/ui/dataset/resources/AddResourceToDataset.ui.xml b/src/main/java/org/gcube/portlets/widgets/ckandatapublisherwidget/client/ui/resources/AddResourceToDataset.ui.xml
similarity index 100%
rename from src/main/java/org/gcube/portlets/widgets/ckandatapublisherwidget/client/ui/dataset/resources/AddResourceToDataset.ui.xml
rename to src/main/java/org/gcube/portlets/widgets/ckandatapublisherwidget/client/ui/resources/AddResourceToDataset.ui.xml
diff --git a/src/main/java/org/gcube/portlets/widgets/ckandatapublisherwidget/client/ui/dataset/resources/AddedResourcesSummary.java b/src/main/java/org/gcube/portlets/widgets/ckandatapublisherwidget/client/ui/resources/AddedResourcesSummary.java
similarity index 99%
rename from src/main/java/org/gcube/portlets/widgets/ckandatapublisherwidget/client/ui/dataset/resources/AddedResourcesSummary.java
rename to src/main/java/org/gcube/portlets/widgets/ckandatapublisherwidget/client/ui/resources/AddedResourcesSummary.java
index fc8db81..33e1ecc 100644
--- a/src/main/java/org/gcube/portlets/widgets/ckandatapublisherwidget/client/ui/dataset/resources/AddedResourcesSummary.java
+++ b/src/main/java/org/gcube/portlets/widgets/ckandatapublisherwidget/client/ui/resources/AddedResourcesSummary.java
@@ -1,4 +1,4 @@
-package org.gcube.portlets.widgets.ckandatapublisherwidget.client.ui.dataset.resources;
+package org.gcube.portlets.widgets.ckandatapublisherwidget.client.ui.resources;
 
 import java.util.ArrayList;
 import java.util.List;
diff --git a/src/main/java/org/gcube/portlets/widgets/ckandatapublisherwidget/client/ui/dataset/resources/AddedResourcesSummary.ui.xml b/src/main/java/org/gcube/portlets/widgets/ckandatapublisherwidget/client/ui/resources/AddedResourcesSummary.ui.xml
similarity index 100%
rename from src/main/java/org/gcube/portlets/widgets/ckandatapublisherwidget/client/ui/dataset/resources/AddedResourcesSummary.ui.xml
rename to src/main/java/org/gcube/portlets/widgets/ckandatapublisherwidget/client/ui/resources/AddedResourcesSummary.ui.xml
diff --git a/src/main/java/org/gcube/portlets/widgets/ckandatapublisherwidget/client/ui/dataset/resources/TagsPanel.java b/src/main/java/org/gcube/portlets/widgets/ckandatapublisherwidget/client/ui/tags/TagsPanel.java
similarity index 96%
rename from src/main/java/org/gcube/portlets/widgets/ckandatapublisherwidget/client/ui/dataset/resources/TagsPanel.java
rename to src/main/java/org/gcube/portlets/widgets/ckandatapublisherwidget/client/ui/tags/TagsPanel.java
index b6e5c75..7ba74f9 100644
--- a/src/main/java/org/gcube/portlets/widgets/ckandatapublisherwidget/client/ui/dataset/resources/TagsPanel.java
+++ b/src/main/java/org/gcube/portlets/widgets/ckandatapublisherwidget/client/ui/tags/TagsPanel.java
@@ -1,4 +1,5 @@
-package org.gcube.portlets.widgets.ckandatapublisherwidget.client.ui.dataset.resources;
+package org.gcube.portlets.widgets.ckandatapublisherwidget.client.ui.tags;
+
 
 import java.util.ArrayList;
 import java.util.List;
@@ -26,6 +27,10 @@ import com.google.gwt.user.client.ui.FlowPanel;
 import com.google.gwt.user.client.ui.FocusPanel;
 import com.google.gwt.user.client.ui.Widget;
 
+/**
+ * Panel for tags.
+ * @author Costantino Perciante at ISTI-CNR (costantino.perciante@isti.cnr.it)
+ */
 public class TagsPanel extends Composite{
 
 	private static TagsPanelUiBinder uiBinder = GWT
@@ -42,9 +47,8 @@ public class TagsPanel extends Composite{
 	@UiField ControlGroup tagsInsertGroup;
 	@UiField ListBox tagsEnterListBox;
 
-
 	// regular expression for tags
-	private static final String REGEX_TAG = "^[a-zA-Z0-9_\\-.]*$";
+	private static final String REGEX_TAG = "^[a-zA-Z0-9]*$";
 
 	// tags list
 	private List<String> tagsList = new ArrayList<String>();
@@ -54,6 +58,8 @@ public class TagsPanel extends Composite{
 	public TagsPanel() {
 		initWidget(uiBinder.createAndBindUi(this));
 		tagsEnterListBox.setVisible(false);
+		tagsPanel.clear();
+		tagsList.clear();
 	}
 
 
@@ -78,6 +84,8 @@ public class TagsPanel extends Composite{
 			tagsEnterListBox.setVisible(true);
 		}
 
+		tagsPanel.clear();
+		tagsList.clear();
 	}
 
 	/**
@@ -269,4 +277,4 @@ public class TagsPanel extends Composite{
 		tagsInsertGroup.setType(type);
 
 	}
-}
+}
\ No newline at end of file
diff --git a/src/main/java/org/gcube/portlets/widgets/ckandatapublisherwidget/client/ui/dataset/resources/TagsPanel.ui.xml b/src/main/java/org/gcube/portlets/widgets/ckandatapublisherwidget/client/ui/tags/TagsPanel.ui.xml
similarity index 100%
rename from src/main/java/org/gcube/portlets/widgets/ckandatapublisherwidget/client/ui/dataset/resources/TagsPanel.ui.xml
rename to src/main/java/org/gcube/portlets/widgets/ckandatapublisherwidget/client/ui/tags/TagsPanel.ui.xml