* grids. This class is mainly used when reading in grids from files
* and converting them to deal.II triangulations.
*
+ * Note: In contrast to the rest of the deal.II library this class
+ * uses the old deal.II numbering scheme, which was used up to deal.II
+ * version 5.2. That is, the vertex and face ordering in 2d is assumed
+ * to be
+ * @verbatim
+ * 2
+ * 3--->---2
+ * | |
+ * 3^ ^1
+ * | |
+ * 0--->---1
+ * 0
+ * @endverbatim
+ * the vertices in 3d:
+ * @verbatim
+ * 7-------6
+ * /| |
+ * / | |
+ * / | |
+ * 3 | |
+ * | 4-------5
+ * | / /
+ * | / /
+ * |/ /
+ * 0-------1
+ * @endverbatim
+ * and the faces in 3d:
+ * @verbatim
+ * *-------* *-------*
+ * /| | / /|
+ * / | 1 | / 4 / |
+ * / | | / / |
+ * * | | *-------* |
+ * | 5 *-------* | | 3 *
+ * | / / | | /
+ * | / 2 / | 0 | /
+ * |/ / | |/
+ * *-------* *-------*
+ * @endverbatim
+ *
+ * After calling the GridReordering::reorder_cells() function the
+ * CellData is still in this old numbering scheme. Hence, for creating
+ * a Triangulation based on the resulting CellData the
+ * Triangulation::create_triangulation_compatibility() (and not the
+ * Triangulation::create_triangulation()) function must be used. For
+ * a typical use of the reorder_cells() function see the
+ * implementation of the GridIn <tt>::read_*()</tt> functions.
+ *
*
* <h3>Statement of problems</h3>
*