From 495b3d4c5e8807552ad92d91fe9ac0f8f08de240 Mon Sep 17 00:00:00 2001
From: Wolfgang Bangerth <bangerth@math.tamu.edu>
Date: Mon, 10 Aug 2015 15:13:47 -0500
Subject: [PATCH] Update documentation of CellAccessor::active_cell_index().

---
 include/deal.II/grid/tria_accessor.h | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/include/deal.II/grid/tria_accessor.h b/include/deal.II/grid/tria_accessor.h
index a3da804d1c..fcc3f7a2b0 100644
--- a/include/deal.II/grid/tria_accessor.h
+++ b/include/deal.II/grid/tria_accessor.h
@@ -2467,7 +2467,12 @@ public:
    * and
    * @ref GlossArtificialCell).
    * This function counts over all of them, including ghost and artificial
-   * active cells.
+   * active cells. This implies that the index returned by this function
+   * uniquely identifies a cell within the triangulation on a single processor,
+   * but does not uniquely identify the cell among the (parts of the)
+   * triangulation that is shared among processors. If you would like to identify
+   * active cells across processors, you need to consider the CellId of a cell
+   * returned by CellAccessor::id().
    */
   unsigned int active_cell_index () const;
 
-- 
2.39.5