Update doc for VTKFlags::write_higher_order_cells.

diff --git a/include/deal.II/base/data_out_base.h b/include/deal.II/base/data_out_base.h
index 3eddfacaa227d28e21b37a1ab4b422e35ee3e30f..9779311bf29d5c69bb28dfb42de3f810b8c21905 100644 (file)
--- a/include/deal.II/base/data_out_base.h
+++ b/include/deal.II/base/data_out_base.h
@@ -1166,14 +1166,14 @@ namespace DataOutBase
      *
      * @note The ability to write data that corresponds to higher order
      * polynomials rather than simply linear or bilinear is a feature that was
-     * only introduced in VTK sometime in 2017 or 2018. You will need at least
-     * Paraview version 5.5 (released in the spring of 2018) or a similarly
-     * recent version of VisIt for this feature to work (for example,
-     * VisIt 2.13.2, released in May 2018, does not yet support this feature).
-     * Older versions of these programs are likely going to result in errors
-     * when trying to read files generated with this flag set to @p true.
-     * Experience with these programs shows that these error messages are likely
-     * going to be rather less descriptive and more obscure.
+     * only introduced in VTK 8.1.0 in December 2017. You will need at least
+     * Paraview version 5.5.0 released in April 2018 or a similarly recent
+     * version of VisIt for this feature to work (for example, VisIt 3.1.1,
+     * released in February 2020, does not yet support this feature). Older
+     * versions of these programs are likely going to result in errors when
+     * trying to read files generated with this flag set to true. Experience
+     * with these programs shows that these error messages are likely going to
+     * be rather less descriptive and more obscure.
      */
     bool write_higher_order_cells;