diff --git a/Boolean_set_operations_2/include/CGAL/Boolean_set_operations_2/Gps_agg_meta_traits.h b/Boolean_set_operations_2/include/CGAL/Boolean_set_operations_2/Gps_agg_meta_traits.h
index 04c869eb60b..b3e7f53173a 100644
--- a/Boolean_set_operations_2/include/CGAL/Boolean_set_operations_2/Gps_agg_meta_traits.h
+++ b/Boolean_set_operations_2/include/CGAL/Boolean_set_operations_2/Gps_agg_meta_traits.h
@@ -141,34 +141,34 @@ class Gps_agg_meta_traits :
   typedef typename Traits::Has_left_category      Has_left_category;
   typedef typename Traits::Has_merge_category     Has_merge_category;
 
-  typedef typename Arrangement::Arr_left_side_tag   Arr_left_side_tag;
-  typedef typename Arrangement::Arr_bottom_side_tag Arr_bottom_side_tag;
-  typedef typename Arrangement::Arr_top_side_tag    Arr_top_side_tag;
-  typedef typename Arrangement::Arr_right_side_tag  Arr_right_side_tag;
+  typedef typename Arrangement::Arr_left_side_category   Arr_left_side_category;
+  typedef typename Arrangement::Arr_bottom_side_category Arr_bottom_side_category;
+  typedef typename Arrangement::Arr_top_side_category    Arr_top_side_category;
+  typedef typename Arrangement::Arr_right_side_category  Arr_right_side_category;
 
   // a side is either oblivious or open (unbounded)
   BOOST_MPL_ASSERT(
       (boost::mpl::or_< 
-       boost::is_same< Arr_left_side_tag, Arr_oblivious_side_tag >,
-       boost::is_same< Arr_left_side_tag, Arr_open_side_tag > >
+       boost::is_same< Arr_left_side_category, Arr_oblivious_side_tag >,
+       boost::is_same< Arr_left_side_category, Arr_open_side_tag > >
       )
   );
   BOOST_MPL_ASSERT(
       (boost::mpl::or_< 
-       boost::is_same< Arr_bottom_side_tag, Arr_oblivious_side_tag >,
-       boost::is_same< Arr_bottom_side_tag, Arr_open_side_tag > >
+       boost::is_same< Arr_bottom_side_category, Arr_oblivious_side_tag >,
+       boost::is_same< Arr_bottom_side_category, Arr_open_side_tag > >
       )
   );
   BOOST_MPL_ASSERT(
       (boost::mpl::or_< 
-       boost::is_same< Arr_top_side_tag, Arr_oblivious_side_tag >,
-       boost::is_same< Arr_top_side_tag, Arr_open_side_tag > >
+       boost::is_same< Arr_top_side_category, Arr_oblivious_side_tag >,
+       boost::is_same< Arr_top_side_category, Arr_open_side_tag > >
       )
   );
   BOOST_MPL_ASSERT(
       (boost::mpl::or_< 
-       boost::is_same< Arr_right_side_tag, Arr_oblivious_side_tag >,
-       boost::is_same< Arr_right_side_tag, Arr_open_side_tag > >
+       boost::is_same< Arr_right_side_category, Arr_oblivious_side_tag >,
+       boost::is_same< Arr_right_side_category, Arr_open_side_tag > >
       )
   );
 
diff --git a/Boolean_set_operations_2/include/CGAL/Boolean_set_operations_2/Gps_agg_op_visitor.h b/Boolean_set_operations_2/include/CGAL/Boolean_set_operations_2/Gps_agg_op_visitor.h
index d129bfc803f..a67100b07a4 100644
--- a/Boolean_set_operations_2/include/CGAL/Boolean_set_operations_2/Gps_agg_op_visitor.h
+++ b/Boolean_set_operations_2/include/CGAL/Boolean_set_operations_2/Gps_agg_op_visitor.h
@@ -38,10 +38,10 @@ class Gps_agg_op_base_visitor :
     // TODO derive (helper) from topology traits class
     typename boost::mpl::if_< 
     boost::is_same< typename Arr_are_all_sides_oblivious_tag< 
-                                     typename Traits::Arr_left_side_tag, 
-                                     typename Traits::Arr_bottom_side_tag, 
-                                     typename Traits::Arr_top_side_tag, 
-                                     typename Traits::Arr_right_side_tag 
+                                     typename Traits::Arr_left_side_category, 
+                                     typename Traits::Arr_bottom_side_category, 
+                                     typename Traits::Arr_top_side_category, 
+                                     typename Traits::Arr_right_side_category 
     >::result, Arr_all_sides_oblivious_tag >,
     Arr_bounded_planar_construction_helper<Traits, 
                                        Arrangement_,
@@ -61,10 +61,10 @@ class Gps_agg_op_base_visitor :
   
   typedef typename boost::mpl::if_< 
     boost::is_same< typename Arr_are_all_sides_oblivious_tag< 
-                                     typename Traits::Arr_left_side_tag, 
-                                     typename Traits::Arr_bottom_side_tag, 
-                                     typename Traits::Arr_top_side_tag, 
-                                     typename Traits::Arr_right_side_tag 
+                                     typename Traits::Arr_left_side_category, 
+                                     typename Traits::Arr_bottom_side_category, 
+                                     typename Traits::Arr_top_side_category, 
+                                     typename Traits::Arr_right_side_category 
     >::result, Arr_all_sides_oblivious_tag >,
     Arr_bounded_planar_construction_helper<Traits, 
                                        Arrangement,
diff --git a/Boolean_set_operations_2/include/CGAL/Boolean_set_operations_2/Gps_traits_decorator.h b/Boolean_set_operations_2/include/CGAL/Boolean_set_operations_2/Gps_traits_decorator.h
index 0ff5dbaf3a3..fabfcef1bf8 100644
--- a/Boolean_set_operations_2/include/CGAL/Boolean_set_operations_2/Gps_traits_decorator.h
+++ b/Boolean_set_operations_2/include/CGAL/Boolean_set_operations_2/Gps_traits_decorator.h
@@ -52,34 +52,34 @@ public:
   typedef typename Base::Has_left_category         Has_left_category;
   typedef typename Base::Has_merge_category        Has_merge_category;
 
-  typedef typename Base::Arr_left_side_tag         Arr_left_side_tag;
-  typedef typename Base::Arr_bottom_side_tag       Arr_bottom_side_tag;
-  typedef typename Base::Arr_top_side_tag          Arr_top_side_tag;
-  typedef typename Base::Arr_right_side_tag        Arr_right_side_tag;
+  typedef typename Base::Arr_left_side_category         Arr_left_side_category;
+  typedef typename Base::Arr_bottom_side_category       Arr_bottom_side_category;
+  typedef typename Base::Arr_top_side_category          Arr_top_side_category;
+  typedef typename Base::Arr_right_side_category        Arr_right_side_category;
 
   // a side is either oblivious or open (unbounded)
   BOOST_MPL_ASSERT(
       (boost::mpl::or_< 
-       boost::is_same< Arr_left_side_tag, Arr_oblivious_side_tag >,
-       boost::is_same< Arr_left_side_tag, Arr_open_side_tag > >
+       boost::is_same< Arr_left_side_category, Arr_oblivious_side_tag >,
+       boost::is_same< Arr_left_side_category, Arr_open_side_tag > >
       )
   );
   BOOST_MPL_ASSERT(
       (boost::mpl::or_< 
-       boost::is_same< Arr_bottom_side_tag, Arr_oblivious_side_tag >,
-       boost::is_same< Arr_bottom_side_tag, Arr_open_side_tag > >
+       boost::is_same< Arr_bottom_side_category, Arr_oblivious_side_tag >,
+       boost::is_same< Arr_bottom_side_category, Arr_open_side_tag > >
       )
   );
   BOOST_MPL_ASSERT(
       (boost::mpl::or_< 
-       boost::is_same< Arr_top_side_tag, Arr_oblivious_side_tag >,
-       boost::is_same< Arr_top_side_tag, Arr_open_side_tag > >
+       boost::is_same< Arr_top_side_category, Arr_oblivious_side_tag >,
+       boost::is_same< Arr_top_side_category, Arr_open_side_tag > >
       )
   );
   BOOST_MPL_ASSERT(
       (boost::mpl::or_< 
-       boost::is_same< Arr_right_side_tag, Arr_oblivious_side_tag >,
-       boost::is_same< Arr_right_side_tag, Arr_open_side_tag > >
+       boost::is_same< Arr_right_side_category, Arr_oblivious_side_tag >,
+       boost::is_same< Arr_right_side_category, Arr_open_side_tag > >
       )
   );