diff -r e550ff884799 -r c2adb9c9c4f0 src/pyams_skin/interfaces/__init__.py
--- a/src/pyams_skin/interfaces/__init__.py	Wed Apr 01 10:44:47 2015 +0200
+++ b/src/pyams_skin/interfaces/__init__.py	Tue Apr 14 16:34:46 2015 +0200
@@ -91,7 +91,12 @@
 class IPageHeader(Interface):
     """Page header interface used by 'header' content provider"""
 
-    back_url = TextLine(title="Back URL target")
+    back_url = TextLine(title="Back URL",
+                        required=False)
+
+    back_target = TextLine(title="Back URL target",
+                           description="HTML target selector, or None for full page target",
+                           required=False)
 
     icon_class = TextLine(title='Icon CSS class')