diff -r f0535129def6 -r cdab3aadc679 misc/migration/3.5.0_Any.py
--- a/misc/migration/3.5.0_Any.py	Wed Mar 27 14:53:40 2013 +0100
+++ b/misc/migration/3.5.0_Any.py	Wed Mar 27 15:38:05 2013 +0100
@@ -1,10 +1,1 @@
-add_relation_type('prefered_form')
-
-rql('SET X prefered_form Y WHERE Y canonical TRUE, X identical_to Y')
-commit()
-
-drop_attribute('EmailAddress', 'canonical')
-drop_relation_definition('EmailAddress', 'identical_to', 'EmailAddress')
-
-if 'see_also' in schema:
-    sync_schema_props_perms('see_also', syncprops=False, syncrdefs=False)
+raise NotImplementedError("Cannot migrate such an old version. Use intermediate Cubiweb version (try 3.16.x)")