1 files changed, 5 insertions, 1 deletions

diff --git a/src/buffer.c b/src/buffer.c
index 209e29f0f19..ea785bbcd70 100644
--- a/src/buffer.c
+++ b/src/buffer.c
@@ -5659,7 +5659,11 @@ This variable is never applied to a way of decoding a file while reading it.  */
 
   DEFVAR_PER_BUFFER ("bidi-display-reordering",
                      &BVAR (current_buffer, bidi_display_reordering), Qnil,
-                     doc: /* Non-nil means reorder bidirectional text for display in the visual order.  */);
+                     doc: /* Non-nil means reorder bidirectional text for display in the visual order.
+Setting this to nil is intended for use in debugging the display code.
+Don't set to nil in normal sessions, as that is not supported.
+See also `bidi-paragraph-direction'; setting that non-nil might
+speed up redisplay.  */);
 
   DEFVAR_PER_BUFFER ("bidi-paragraph-start-re",
                      &BVAR (current_buffer, bidi_paragraph_start_re), Qnil,