diff --git a/Envelope_3/doc/Envelope_3/CGAL/Env_surface_data_traits_3.h b/Envelope_3/doc/Envelope_3/CGAL/Env_surface_data_traits_3.h
index bcd4f97ab41..cdfb26c219f 100644
--- a/Envelope_3/doc/Envelope_3/CGAL/Env_surface_data_traits_3.h
+++ b/Envelope_3/doc/Envelope_3/CGAL/Env_surface_data_traits_3.h
@@ -1,84 +1,64 @@
 namespace CGAL {
 
-/*!
-\ingroup PkgEnvelope3Ref
-
-The class `Env_surface_data_traits_3` is a model of the `EnvelopeTraits_3` concept
-and serves as a decorator class that allows the extension of the surfaces
-defined by the base traits-class (the `Traits` parameter), which serves
-as a geometric traits-class (a model of the `EnvelopeTraits_3` concept),
-with extraneous (non-geometric) data fields.
-
-The traits-class decorator extends the `Surface_3` and the
-`Xy_monotone_surface_3` types as detailed below.
-Each `Surface_3` object is associated with a single data field of type
-`SData`, and each `Xy_monotone_surface_3` object is associated with
-a single data field of type `XyData`. When a surface is
-subdivided into \f$ xy\f$-monotone surfaces, its data field is converted using
-the conversion functor, which is specified by the `Cnv` template-parameter,
-and the resulting objects is copied to all `Xy_monotone_surface_3` objects
-induced by this surface. The conversion functor should provide an operator with
-the following prototype:
-
-`XyData operator() (const SData& d) const;`
-
-By default, the two data types are the same, so the conversion operator
-is trivial and just copies the data object:
-
-<TABLE><TR><TD>
-`SData` =
-</TD>
-<TD>
-`XyData`
-</TD></TR>
-<TR><TD>
-`Cnv` =
-</TD>
-<TD>
-`_Default_convert_functor<SData,XyData>`
-</TD></TR>
-</TABLE>
-
-\cgalModels{EnvelopeTraits_3}
-
-*/
-template< typename Traits, typename XyData, typename SData, typename Cnv >
+/*! \ingroup PkgEnvelope3Ref
+ *
+ * The class `Env_surface_data_traits_3` is a model of the `EnvelopeTraits_3`
+ * concept and serves as a decorator class that allows the extension of the
+ * surfaces defined by the base traits-class (the `Traits` parameter), which
+ * serves as a geometric traits-class (a model of the `EnvelopeTraits_3`
+ * concept), with extraneous (non-geometric) data fields.
+ *
+ * The traits-class decorator extends the `Surface_3` and the
+ * `Xy_monotone_surface_3` types as detailed below.  Each `Surface_3` object is
+ * associated with a single data field of type `SData`, and each
+ * `Xy_monotone_surface_3` object is associated with a single data field of type
+ * `XyData`. When a surface is subdivided into \f$ xy\f$-monotone surfaces, its
+ * data field is converted using the conversion functor, which is specified by
+ * the `Cnv` template-parameter, and the resulting objects is copied to all
+ * `Xy_monotone_surface_3` objects induced by this surface. The conversion
+ * functor should provide an operator with the following prototype:
+ *
+ * `XyData operator() (const SData& d) const;`
+ *
+ * By default, the two data types are the same, so the conversion operator
+ * is trivial and just copies the data object:
+ *
+ * <TABLE><TR>
+ * <TD>`SData` =</TD>
+ * <TD>`XyData`</TD>
+ * </TR>
+ * <TR>
+ * <TD>`Cnv` =</TD>
+ * <TD>`_Default_convert_functor<SData,XyData>`</TD>
+ * </TR></TABLE>
+ *
+ * \cgalModels{EnvelopeTraits_3}
+ *
+ */
+template <typename Traits, typename XyData, typename SData, typename Cnv>
 class Env_surface_data_traits_3 : public Traits {
 public:
 
-/// \name Types
-/// @{
+  /// \name Types
+  /// @{
 
-/*!
-the base traits-class.
-*/
-typedef Traits Base_traits_3;
+  //! the base traits-class.
+  typedef Traits Base_traits_3;
 
-/*!
-the base surface.
-*/
-typedef typename Base_traits_3::Surface_3 Base_surface_3;
+  //! the base surface.
+  typedef typename Base_traits_3::Surface_3 Base_surface_3;
 
-/*!
-the base \f$ xy\f$-monotone surface surface.
-*/
-typedef typename Base_traits_3::Xy_monotone_surface_3 Base_xy_monotone_surface_3;
+  //! the base \f$ xy\f$-monotone surface surface.
+  typedef typename Base_traits_3::Xy_monotone_surface_3 Base_xy_monotone_surface_3;
 
-/*!
-the conversion functor.
-*/
-typedef Cnv Convert;
+  //! the conversion functor.
+  typedef Cnv Convert;
 
-/*!
-the type of data associated with surfaces.
-*/
-typedef SData Surface_data;
-
-/*!
-the type of data associated with \f$ xy\f$-monotone surfaces.
-*/
-typedef XyData Xy_monotone_surface_data;
+  //! the type of data associated with surfaces.
+  typedef SData Surface_data;
 
+  //! the type of data associated with \f$ xy\f$-monotone surfaces.
+  typedef XyData Xy_monotone_surface_data;
 
   /// The `Surface_3` class nested within the surface-data traits
   /// extends the `Base_traits_3::Surface_3` type with an extra data field.
@@ -87,38 +67,33 @@ typedef XyData Xy_monotone_surface_data;
     /// \name Creation
     /// @{
 
-    /*!
-    default constructor.
-    */
-    Surface_3 ();
+    /*! default constructor.
+     */
+    Surface_3();
 
-    /*!
-    constructs surface from the given `base` surface with uninitialized
-    data field.
-    */
-    Surface_3 (const Base_surface_3& base);
+    /*! constructs surface from the given `base` surface with uninitialized
+     * data field.
+     */
+    Surface_3(const Base_surface_3& base);
 
-    /*!
-    constructs surface from the given `base` surface with an attached
-    `data` field.
-    */
-    Surface_3 (const Base_surface_3& base, const Surface_data& data);
+    /*! constructs surface from the given `base` surface with an attached
+     * `data` field.
+     */
+    Surface_3(const Base_surface_3& base, const Surface_data& data);
 
     /// @}
 
     /// \name Access Functions
     /// @{
 
-    /*!
-    returns the data field (a non-const version, which returns a reference
-    to the data object, is also available).
-    */
+    /*! returns the data field (a non-const version, which returns a reference
+     * to the data object, is also available).
+     */
     const Surface_data& data () const;
 
-    /*!
-    sets the data field.
-    */
-    void set_data (const Surface_data& data);
+    /*! sets the data field.
+     */
+    void set_env_data (const Surface_data& data);
 
     /// @}
   };
@@ -131,22 +106,19 @@ typedef XyData Xy_monotone_surface_data;
     /// \name Creation
     /// @{
 
-    /*!
-    default constructor.
-    */
+    /*! default constructor.
+     */
     Xy_monotone_surface_3 ();
 
-    /*!
-    constructs an \f$ xy\f$-monotone surface from the given `base` surface with
-    uninitialized data field.
-    */
-    Xy_monotone_surface_3 (const Base_xy_monotone_surface_3& base);
+    /*! constructs an \f$ xy\f$-monotone surface from the given `base` surface
+     * with uninitialized data field.
+     */
+    Xy_monotone_surface_3(const Base_xy_monotone_surface_3& base);
 
-    /*!
-    constructs an \f$ x\f$-monotone surface from the given `base` \f$ x\f$-monotone
-    surface with an attached `data` field.
-    */
-    Xy_monotone_surface_3 (const Base_xy_monotone_surface_3& base,
+    /*! constructs an \f$ x\f$-monotone surface from the given `base`
+     * \f$ x\f$-monotone surface with an attached `data` field.
+     */
+    Xy_monotone_surface_3(const Base_xy_monotone_surface_3& base,
     const Xy_monotone_surface_data& data);
 
     /// @}
@@ -154,21 +126,20 @@ typedef XyData Xy_monotone_surface_data;
     /// \name Access Functions
     /// @{
 
-    /*!
-    returns the field (a non-const version, which returns a reference
-    to the data object, is also available).
-    */
-    const Xy_monotone_surface_data& data () const;
+    /*! returns the field (a non-const version, which returns a reference
+     * to the data object, is also available).
+     */
+    const Xy_monotone_surface_data& data() const;
 
-    /*!
-    sets the data field.
-    */
-    void set_data (const Xy_monotone_surface_data& data);
+    /*! sets the data field.
+     */
+    void set_env_data(const Xy_monotone_surface_data& data);
 
     /// @}
   };
 
-/// @}
+  /// @}
 
 }; /* end */
+
 } /* end namespace CGAL */