-<li>\ref display_entity_page "Display Entity" - allows to display
-Faces, Edges or both.</li>
-<li><b>Colors / Size</b> - allows to select color and size of
-meshes.</li>
-<li>\ref transparency_page "Transparency" - allows to change the
+<li>\subpage display_entity_page "Display Entity" - allows to display
+entities by types (Faces, Edges, Volumes etc.).</li>
+<li><b>2D Quadratic</b> - allows to select between the representation
+of quadratic edges as broken <b>lines</b> or as <b>arcs</b></li>
+<li><b>Orientation of faces</b> - shows vectors of orientation of
+faces of the selected mesh. The orientation vector is shown for each 2D mesh element
+and for each free face of a 3D mesh element. the vector direction is calculated by
+the first three nodes of the face produced by vectors n1-n2 and n1-n3.</li>
+<li>\subpage colors_size_page "Properties" - allows to define several properties, including color of elements, shrink size, ....</li>
+<li>\subpage transparency_page "Transparency" - allows to change the