(syms_of_buffer): Doc fix.

diff --git a/src/buffer.c b/src/buffer.c
index a2bff81ebd80b824024535c8dd30b6cb9d563f44..16321df850d4fa676c0a7120e16144294836dd9f 100644 (file)
--- a/src/buffer.c
+++ b/src/buffer.c
@@ -3879,6 +3879,8 @@ A string is printed verbatim in the mode line except for %-constructs:\n\
        For a modified read-only buffer, %* gives % and %+ gives *.\n\
   %s -- print process status.   %l -- print the current line number.\n\
   %c -- print the current column number (this makes editing slower).\n\
+        To make the column number update correctly in all cases,\n\
+       `column-number-mode' must be non-nil.\n\
   %p -- print percent of buffer above top of window, or Top, Bot or All.\n\
   %P -- print percent of buffer above bottom of window, perhaps plus Top,\n\
         or print Bottom or All.\n\