diff --git a/Surface_mesher/doc_tex/Surface_mesher/main.tex b/Surface_mesher/doc_tex/Surface_mesher/main.tex
index 7d0a0d27440..7ba244db832 100644
--- a/Surface_mesher/doc_tex/Surface_mesher/main.tex
+++ b/Surface_mesher/doc_tex/Surface_mesher/main.tex
@@ -408,6 +408,20 @@ manifold but may have boundaries.\\
 \ccc{Non_manifold_tag}: the algorithm relies on the given criteria and
 guarantees nothing else.
 
+\section{Undocumented features available in demos}
+
+The Polyhedron demo has a feature that allows to remesh a polyhedral
+surface, using the 3D Surface Mesh Generator. That has been implemented as
+a special model of \ccc{SurfaceMeshTraits_3}, for polyhedra. That traits
+class is not yet documented because its interface and code have not yet
+been stabilized. It will be shipped with next release of CGAL.
+
+The Surface Mesh Generator demo allows to mesh not only gray level images,
+but also segmented images, when voxels are labelled with a domain
+index. Such images are for example the result of a segmentation of 3D
+medical images. This feature is not yet ready to be documented in current
+release, but will be in next release of CGAL.
+
 \section{Design and Implementation History}
 
 The algorithm implemented in this package