diff --git a/GraphicsView/include/CGAL/Buffer_for_vao.h b/GraphicsView/include/CGAL/Buffer_for_vao.h
index 2be331a35f5..cfc1a5d26ca 100644
--- a/GraphicsView/include/CGAL/Buffer_for_vao.h
+++ b/GraphicsView/include/CGAL/Buffer_for_vao.h
@@ -15,7 +15,7 @@
 
 #include <CGAL/license/GraphicsView.h>
 
-#include <CGAL/Triangulation_2_projection_traits_3.h>
+#include <CGAL/Projection_traits_3.h>
 #include <CGAL/Triangulation_vertex_base_with_info_2.h>
 #include <CGAL/Triangulation_face_base_with_info_2.h>
 #include <CGAL/Constrained_Delaunay_triangulation_2.h>
@@ -887,7 +887,7 @@ protected:
     bool is_process;
   };
 
-  typedef CGAL::Triangulation_2_projection_traits_3<CGAL::Exact_predicates_inexact_constructions_kernel> P_traits;
+  typedef CGAL::Projection_traits_3<CGAL::Exact_predicates_inexact_constructions_kernel> P_traits;
   typedef CGAL::Triangulation_vertex_base_with_info_2<Vertex_info, P_traits> Vb;
   typedef CGAL::Triangulation_face_base_with_info_2<Face_info, P_traits>     Fb1;
   typedef CGAL::Constrained_triangulation_face_base_2<P_traits, Fb1>         Fb;
diff --git a/Kernel_23/doc/Kernel_23/CGAL/Triangulation_2_projection_traits_3.h b/Kernel_23/doc/Kernel_23/CGAL/Triangulation_2_projection_traits_3.h
index 019e4d15169..4ee6daf9baf 100644
--- a/Kernel_23/doc/Kernel_23/CGAL/Triangulation_2_projection_traits_3.h
+++ b/Kernel_23/doc/Kernel_23/CGAL/Triangulation_2_projection_traits_3.h
@@ -3,7 +3,7 @@ namespace CGAL{
 /*!
  \ingroup PkgTriangulation2TriangulationClasses
 
-  The class `Triangulation_2_projection_traits_3` works similarly as the `Projection_traits_xy_3`,
+  The class `Projection_traits_3` works similarly as the `Projection_traits_xy_3`,
   `Projection_traits_xz_3` and `Projection_traits_yz_3` traits classes, by enabling
   the use of 2D algorithms on the projections of 3D data on an arbitrary plane.
 
@@ -22,7 +22,7 @@ provides exact predicates.
 
  */
 template <class K>
-class Triangulation_2_projection_traits_3
+class Projection_traits_3
 {
 public:
   ///\name Types
@@ -50,7 +50,7 @@ public:
    *
    * \param normal a vector orthogonal to the projection plane.
    */
-  Triangulation_2_projection_traits_3(const typename K::Vector_3& normal);
+  Projection_traits_3(const typename K::Vector_3& normal);
 
   ///@}
 };
diff --git a/Kernel_23/doc/Kernel_23/PackageDescription.txt b/Kernel_23/doc/Kernel_23/PackageDescription.txt
index 40d72ba9db2..873c5e089a1 100644
--- a/Kernel_23/doc/Kernel_23/PackageDescription.txt
+++ b/Kernel_23/doc/Kernel_23/PackageDescription.txt
@@ -71,7 +71,7 @@
 - `CGAL::Simple_cartesian<FieldNumberType>`
 - `CGAL::Simple_homogeneous<RingNumberType>`
 - `CGAL::Projection_traits_xy_3<K>`
-- `CGAL::Triangulation_2_projection_traits_3<K>`
+- `CGAL::Projection_traits_3<K>`
 
 \cgalCRPSection{Predefined Kernels}
 
diff --git a/Kernel_23/include/CGAL/Triangulation_2_projection_traits_3.h b/Kernel_23/include/CGAL/Projection_traits_3.h
similarity index 69%
rename from Kernel_23/include/CGAL/Triangulation_2_projection_traits_3.h
rename to Kernel_23/include/CGAL/Projection_traits_3.h
index e1998929fe6..f47faf41966 100644
--- a/Kernel_23/include/CGAL/Triangulation_2_projection_traits_3.h
+++ b/Kernel_23/include/CGAL/Projection_traits_3.h
@@ -11,8 +11,8 @@
 // Author(s)     : Laurent Rineau
 
 
-#ifndef CGAL_TRIANGULATION_2_PROJECTION_TRAITS_3_H
-#define CGAL_TRIANGULATION_2_PROJECTION_TRAITS_3_H
+#ifndef CGAL_PROJECTION_TRAITS_3_H
+#define CGAL_PROJECTION_TRAITS_3_H
 
 
 #include <CGAL/internal/Triangulation_2_filtered_projection_traits_3.h>
@@ -24,27 +24,27 @@ template < class Filtered_kernel >
 class Triangulation_2_filtered_projection_traits_3;
 
 template <class Kernel, bool Has_filtered_predicates=Kernel::Has_filtered_predicates>
-class Triangulation_2_projection_traits_3
+class Projection_traits_3
   : public Triangulation_2_projection_traits_base_3<Kernel>
 {
 public:
   explicit
-  Triangulation_2_projection_traits_3(const typename Kernel::Vector_3& n_)
+  Projection_traits_3(const typename Kernel::Vector_3& n_)
     : Triangulation_2_projection_traits_base_3<Kernel>(n_)
   {}
 };
 
 template <class Kernel>
-class Triangulation_2_projection_traits_3<Kernel, true>
+class Projection_traits_3<Kernel, true>
   : public Triangulation_2_filtered_projection_traits_3<Kernel>
 {
 public:
   explicit
-  Triangulation_2_projection_traits_3(const typename Kernel::Vector_3& n_)
+  Projection_traits_3(const typename Kernel::Vector_3& n_)
     : Triangulation_2_filtered_projection_traits_3<Kernel>(n_)
   {}
 };
 
 } // end namespace CGAL
 
-#endif // CGAL_TRIANGULATION_2_PROJECTION_TRAITS_3_H
+#endif // CGAL_PROJECTION_TRAITS_3_H
diff --git a/Linear_cell_complex/demo/Linear_cell_complex/typedefs.h b/Linear_cell_complex/demo/Linear_cell_complex/typedefs.h
index 17924ecca8d..02dbf3a129f 100644
--- a/Linear_cell_complex/demo/Linear_cell_complex/typedefs.h
+++ b/Linear_cell_complex/demo/Linear_cell_complex/typedefs.h
@@ -14,7 +14,7 @@
 
 #include <CGAL/Exact_predicates_inexact_constructions_kernel.h>
 
-#include <CGAL/Triangulation_2_projection_traits_3.h>
+#include <CGAL/Projection_traits_3.h>
 #include <CGAL/Triangulation_vertex_base_with_info_2.h>
 #include <CGAL/Triangulation_face_base_with_info_2.h>
 #include <CGAL/Constrained_Delaunay_triangulation_2.h>
@@ -178,7 +178,7 @@ struct Face_info {
   bool is_process;
 };
 
-typedef CGAL::Triangulation_2_projection_traits_3<CGAL::Exact_predicates_inexact_constructions_kernel> P_traits;
+typedef CGAL::Projection_traits_3<CGAL::Exact_predicates_inexact_constructions_kernel> P_traits;
 typedef CGAL::Triangulation_vertex_base_with_info_2<Vertex_info, P_traits> Vb;
 
 typedef CGAL::Triangulation_face_base_with_info_2<Face_info,P_traits> Fb1;
diff --git a/Linear_cell_complex/examples/Linear_cell_complex/basic_viewer.h b/Linear_cell_complex/examples/Linear_cell_complex/basic_viewer.h
index 6b7b97eb3c1..a40da37927e 100644
--- a/Linear_cell_complex/examples/Linear_cell_complex/basic_viewer.h
+++ b/Linear_cell_complex/examples/Linear_cell_complex/basic_viewer.h
@@ -22,7 +22,7 @@
 #include <QGLBuffer>
 #include <QOpenGLShaderProgram>
 
-#include <CGAL/Triangulation_2_projection_traits_3.h>
+#include <CGAL/Projection_traits_3.h>
 #include <CGAL/Triangulation_vertex_base_with_info_2.h>
 #include <CGAL/Triangulation_face_base_with_info_2.h>
 #include <CGAL/Constrained_Delaunay_triangulation_2.h>
@@ -211,7 +211,7 @@ class Basic_viewer : public CGAL::QGLViewer, public QOpenGLFunctions
     bool is_process;
   };
 
-  typedef CGAL::Triangulation_2_projection_traits_3<CGAL::Exact_predicates_inexact_constructions_kernel> P_traits;
+  typedef CGAL::Projection_traits_3<CGAL::Exact_predicates_inexact_constructions_kernel> P_traits;
   typedef CGAL::Triangulation_vertex_base_with_info_2<Vertex_info, P_traits> Vb;
 
   typedef CGAL::Triangulation_face_base_with_info_2<Face_info, P_traits> Fb1;
diff --git a/Mesh_2/test/Mesh_2/test_mesh_projection_traits.cpp b/Mesh_2/test/Mesh_2/test_mesh_projection_traits.cpp
index 030471c0295..63ed376d7af 100644
--- a/Mesh_2/test/Mesh_2/test_mesh_projection_traits.cpp
+++ b/Mesh_2/test/Mesh_2/test_mesh_projection_traits.cpp
@@ -3,12 +3,12 @@
 #include <CGAL/Delaunay_mesher_2.h>
 #include <CGAL/Delaunay_mesh_face_base_2.h>
 #include <CGAL/Delaunay_mesh_size_criteria_2.h>
-#include <CGAL/Triangulation_2_projection_traits_3.h>
+#include <CGAL/Projection_traits_3.h>
 
 #include <iostream>
 
 typedef CGAL::Exact_predicates_inexact_constructions_kernel K1;
-typedef CGAL::Triangulation_2_projection_traits_3<K1> K;
+typedef CGAL::Projection_traits_3<K1> K;
 typedef CGAL::Triangulation_vertex_base_2<K> Vb;
 typedef CGAL::Delaunay_mesh_face_base_2<K> Fb;
 typedef CGAL::Triangulation_data_structure_2<Vb, Fb> Tds;
diff --git a/Nef_3/include/CGAL/boost/graph/convert_nef_polyhedron_to_polygon_mesh.h b/Nef_3/include/CGAL/boost/graph/convert_nef_polyhedron_to_polygon_mesh.h
index 5f651edb1ab..36608b5eade 100644
--- a/Nef_3/include/CGAL/boost/graph/convert_nef_polyhedron_to_polygon_mesh.h
+++ b/Nef_3/include/CGAL/boost/graph/convert_nef_polyhedron_to_polygon_mesh.h
@@ -22,7 +22,7 @@
 #include <CGAL/Cartesian_converter.h>
 #include <boost/unordered_map.hpp>
 #include <CGAL/Constrained_Delaunay_triangulation_2.h>
-#include <CGAL/Triangulation_2_projection_traits_3.h>
+#include <CGAL/Projection_traits_3.h>
 #include <CGAL/Triangulation_vertex_base_with_info_2.h>
 #include <CGAL/Triangulation_face_base_with_info_2.h>
 #include <CGAL/Kernel/global_functions_3.h>
@@ -211,7 +211,7 @@ struct Shell_polygons_visitor
 
     // cases where a cdt is needed
     typedef typename Nef_polyhedron::Kernel Kernel;
-    typedef Triangulation_2_projection_traits_3<Kernel>            P_traits;
+    typedef Projection_traits_3<Kernel>            P_traits;
     typedef Triangulation_vertex_base_with_info_2<std::size_t, P_traits> Vb;
     typedef Triangulation_face_base_with_info_2<FaceInfo2,P_traits>     Fbb;
     typedef Constrained_triangulation_face_base_2<P_traits,Fbb>          Fb;
diff --git a/Polygon_mesh_processing/include/CGAL/Polygon_mesh_processing/internal/Corefinement/Visitor.h b/Polygon_mesh_processing/include/CGAL/Polygon_mesh_processing/internal/Corefinement/Visitor.h
index a50deb6ae03..6fa77d69bed 100644
--- a/Polygon_mesh_processing/include/CGAL/Polygon_mesh_processing/internal/Corefinement/Visitor.h
+++ b/Polygon_mesh_processing/include/CGAL/Polygon_mesh_processing/internal/Corefinement/Visitor.h
@@ -23,7 +23,7 @@
 #include <CGAL/Default.h>
 #include <CGAL/boost/graph/Euler_operations.h>
 #include <CGAL/Constrained_Delaunay_triangulation_2.h>
-#include <CGAL/Triangulation_2_projection_traits_3.h>
+#include <CGAL/Projection_traits_3.h>
 #include <CGAL/Triangulation_vertex_base_with_info_2.h>
 
 #include <boost/container/flat_map.hpp>
@@ -389,7 +389,7 @@ private:
    typedef Intersection_nodes<TriangleMesh, VertexPointMap1, VertexPointMap2,
             Predicates_on_constructions_needed>                          INodes;
    typedef typename INodes::Exact_kernel                                     EK;
-    typedef Triangulation_2_projection_traits_3<EK>                  CDT_traits;
+    typedef Projection_traits_3<EK>                  CDT_traits;
     typedef Triangulation_vertex_base_with_info_2<Node_id,CDT_traits>        Vb;
     typedef Constrained_triangulation_face_base_2<CDT_traits>                Fb;
     typedef Triangulation_data_structure_2<Vb,Fb>                         TDS_2;
diff --git a/Polygon_mesh_processing/include/CGAL/Polygon_mesh_processing/internal/Hole_filling/Triangulate_hole_polyline.h b/Polygon_mesh_processing/include/CGAL/Polygon_mesh_processing/internal/Hole_filling/Triangulate_hole_polyline.h
index e60dafba2b1..0f014dc5700 100644
--- a/Polygon_mesh_processing/include/CGAL/Polygon_mesh_processing/internal/Hole_filling/Triangulate_hole_polyline.h
+++ b/Polygon_mesh_processing/include/CGAL/Polygon_mesh_processing/internal/Hole_filling/Triangulate_hole_polyline.h
@@ -28,7 +28,7 @@
 #include <CGAL/Triangulation_vertex_base_with_info_2.h>
 #include <CGAL/Triangulation_face_base_with_info_2.h>
 #include <CGAL/Constrained_Delaunay_triangulation_2.h>
-#include <CGAL/Triangulation_2_projection_traits_3.h>
+#include <CGAL/Projection_traits_3.h>
 #include <queue>
 #endif
 
@@ -1374,7 +1374,7 @@ triangulate_hole_polyline_with_cdt(const PointRange& points,
   }
 
   // Checking the hole simplicity.
-  typedef Triangulation_2_projection_traits_3<Traits> P_traits;
+  typedef Projection_traits_3<Traits> P_traits;
   const P_traits p_traits(avg_normal);
   if (!is_simple_2(P.begin(), P.end() - 1, p_traits)) {
     // std::cerr << "WARNING: simplicity, cdt 2 falls back to the original solution!" << std::endl;
diff --git a/Polygon_mesh_processing/include/CGAL/Polygon_mesh_processing/triangulate_faces.h b/Polygon_mesh_processing/include/CGAL/Polygon_mesh_processing/triangulate_faces.h
index a4c38c7b040..a2cc56ae520 100644
--- a/Polygon_mesh_processing/include/CGAL/Polygon_mesh_processing/triangulate_faces.h
+++ b/Polygon_mesh_processing/include/CGAL/Polygon_mesh_processing/triangulate_faces.h
@@ -24,7 +24,7 @@
 #include <CGAL/Triangulation_vertex_base_with_info_2.h>
 #include <CGAL/Triangulation_face_base_with_info_2.h>
 #include <CGAL/Constrained_Delaunay_triangulation_2.h>
-#include <CGAL/Triangulation_2_projection_traits_3.h>
+#include <CGAL/Projection_traits_3.h>
 #else
 #include <CGAL/use.h>
 #endif
@@ -152,7 +152,7 @@ public:
 #ifndef CGAL_TRIANGULATE_FACES_DO_NOT_USE_CDT2
       if (use_cdt)
       {
-        typedef CGAL::Triangulation_2_projection_traits_3<Traits>   P_traits;
+        typedef CGAL::Projection_traits_3<Traits>   P_traits;
         typedef CGAL::Triangulation_vertex_base_with_info_2<halfedge_descriptor,
                                                             P_traits>        Vb;
         typedef CGAL::Triangulation_face_base_with_info_2<Face_info,
diff --git a/Polyhedron/demo/Polyhedron/Scene_lcc_item.cpp b/Polyhedron/demo/Polyhedron/Scene_lcc_item.cpp
index 41b16a37b9c..e143810c595 100644
--- a/Polyhedron/demo/Polyhedron/Scene_lcc_item.cpp
+++ b/Polyhedron/demo/Polyhedron/Scene_lcc_item.cpp
@@ -154,7 +154,7 @@ struct lcc_priv{
         bool is_process;
       };
 
-      typedef CGAL::Triangulation_2_projection_traits_3<CGAL::Exact_predicates_inexact_constructions_kernel> P_traits;
+      typedef CGAL::Projection_traits_3<CGAL::Exact_predicates_inexact_constructions_kernel> P_traits;
       typedef CGAL::Triangulation_vertex_base_with_info_2<Vertex_info, P_traits> Vb;
       typedef CGAL::Triangulation_face_base_with_info_2<Face_info, P_traits>     Fb1;
       typedef CGAL::Constrained_triangulation_face_base_2<P_traits, Fb1>         Fb;
diff --git a/Polyhedron/demo/Polyhedron/Scene_nef_polyhedron_item.cpp b/Polyhedron/demo/Polyhedron/Scene_nef_polyhedron_item.cpp
index af27d7c18b2..2f3ee485b95 100644
--- a/Polyhedron/demo/Polyhedron/Scene_nef_polyhedron_item.cpp
+++ b/Polyhedron/demo/Polyhedron/Scene_nef_polyhedron_item.cpp
@@ -18,7 +18,7 @@
 #include <CGAL/minkowski_sum_3.h>
 #include <CGAL/convex_decomposition_3.h>
 
-#include <CGAL/Triangulation_2_projection_traits_3.h>
+#include <CGAL/Projection_traits_3.h>
 #include <CGAL/Triangulation_vertex_base_with_info_2.h>
 #include <CGAL/Triangulation_face_base_with_info_2.h>
 #include <CGAL/boost/graph/convert_nef_polyhedron_to_polygon_mesh.h>
@@ -33,7 +33,7 @@ typedef Point_container Pc;
 
 typedef Nef_polyhedron::Traits Traits;
 typedef Nef_polyhedron::Halffacet Facet;
-typedef CGAL::Triangulation_2_projection_traits_3<Traits>   P_traits;
+typedef CGAL::Projection_traits_3<Traits>   P_traits;
 typedef Nef_polyhedron::Halfedge_const_handle Halfedge_handle;
 struct Face_info {
     Nef_polyhedron::Halfedge_const_handle e[3];
diff --git a/Polyhedron/demo/Polyhedron/triangulate_primitive.h b/Polyhedron/demo/Polyhedron/triangulate_primitive.h
index bae5804da1b..a1f96c9f2bf 100644
--- a/Polyhedron/demo/Polyhedron/triangulate_primitive.h
+++ b/Polyhedron/demo/Polyhedron/triangulate_primitive.h
@@ -3,7 +3,7 @@
 #include <CGAL/Triangulation_vertex_base_with_info_2.h>
 #include <CGAL/Triangulation_face_base_with_info_2.h>
 #include <CGAL/Constrained_Delaunay_triangulation_2.h>
-#include <CGAL/Triangulation_2_projection_traits_3.h>
+#include <CGAL/Projection_traits_3.h>
 #include <CGAL/Three/Scene_item.h>
 #include <queue>
 
@@ -20,7 +20,7 @@ class FacetTriangulator
  typedef typename Kernel::Vector_3 Vector;
 
 
- typedef CGAL::Triangulation_2_projection_traits_3<Traits>   P_traits;
+ typedef CGAL::Projection_traits_3<Traits>   P_traits;
 
  typedef CGAL::Triangulation_vertex_base_with_info_2<halfedge_descriptor,
                                                      P_traits>        Vb;
diff --git a/Triangulation_2/doc/Triangulation_2/Triangulation_2.txt b/Triangulation_2/doc/Triangulation_2/Triangulation_2.txt
index 299b4239965..8a1deae2c55 100644
--- a/Triangulation_2/doc/Triangulation_2/Triangulation_2.txt
+++ b/Triangulation_2/doc/Triangulation_2/Triangulation_2.txt
@@ -488,7 +488,7 @@ See Section \ref Section_2D_Triangulations_Delaunay for an example.
 deal with projections on the
 `yz` plane and `xz`-plane,
 respectively, as well as the geometric traits class
-`Triangulation_2_projection_traits_3` that deals with projections on an
+`Projection_traits_3` that deals with projections on an
 arbitrary plane, defined by its orthogonal vector.
 
 \subsection Subsection_2D_Triangulations_Basic_Example Example of a Basic Triangulation
diff --git a/Triangulation_2/examples/Triangulation_2/projection_traits.cpp b/Triangulation_2/examples/Triangulation_2/projection_traits.cpp
index 32812a543c3..37d691d6243 100644
--- a/Triangulation_2/examples/Triangulation_2/projection_traits.cpp
+++ b/Triangulation_2/examples/Triangulation_2/projection_traits.cpp
@@ -1,12 +1,12 @@
 #include <CGAL/Exact_predicates_inexact_constructions_kernel.h>
 #include <CGAL/Constrained_Delaunay_triangulation_2.h>
-#include <CGAL/Triangulation_2_projection_traits_3.h>
+#include <CGAL/Projection_traits_3.h>
 
 #include <iostream>
 #include <vector>
 
 typedef CGAL::Exact_predicates_inexact_constructions_kernel                K1;
-typedef CGAL::Triangulation_2_projection_traits_3<K1>                      K;
+typedef CGAL::Projection_traits_3<K1>                      K;
 
 typedef CGAL::Exact_predicates_tag                                         Itag;
 typedef CGAL::Constrained_Delaunay_triangulation_2<K, CGAL::Default, Itag> CDT;
diff --git a/Triangulation_2/test/Triangulation_2/test_cdt_2_projection_traits_special_case.cpp b/Triangulation_2/test/Triangulation_2/test_cdt_2_projection_traits_special_case.cpp
index 26693b95a28..6fcaca74953 100644
--- a/Triangulation_2/test/Triangulation_2/test_cdt_2_projection_traits_special_case.cpp
+++ b/Triangulation_2/test/Triangulation_2/test_cdt_2_projection_traits_special_case.cpp
@@ -1,8 +1,8 @@
 #include <CGAL/Exact_predicates_inexact_constructions_kernel.h>
 #include <CGAL/Exact_predicates_exact_constructions_kernel.h>
 #include <CGAL/Constrained_Delaunay_triangulation_2.h>
-#include <CGAL/Triangulation_2_projection_traits_3.h>
-#include <CGAL/Triangulation_2_projection_traits_3.h>
+#include <CGAL/Projection_traits_3.h>
+#include <CGAL/Projection_traits_3.h>
 
 #include <string>
 #include <fstream>
@@ -69,11 +69,11 @@ int main()
   bool ok = true;
   ok = ok &&
       test<CGAL::Epick,
-           CGAL::Triangulation_2_projection_traits_3<Epick> >
+           CGAL::Projection_traits_3<Epick> >
       ("CDT_2 in a 3D plane, with Epick");
   ok = ok &&
       test<CGAL::Epeck,
-           CGAL::Triangulation_2_projection_traits_3<Epeck> >
+           CGAL::Projection_traits_3<Epeck> >
       ("CDT_2 in a 3D plane, with Epeck");
   return ok ? 0 : 1;
 }