1 files changed, 6 insertions, 1 deletions

diff --git a/src/buffer.c b/src/buffer.c
index ff4a500c8b7..80dbd3318dc 100644
--- a/src/buffer.c
+++ b/src/buffer.c
@@ -5486,8 +5486,11 @@ A string is printed verbatim in the mode line except for %-constructs:
         For a modified read-only buffer, %* gives % and %+ gives *.
   %s -- print process status.   %l -- print the current line number.
   %c -- print the current column number (this makes editing slower).
+        Columns are numbered starting from the left margin, and the
+        leftmost column is displayed as zero.
         To make the column number update correctly in all cases,
         `column-number-mode' must be non-nil.
+  %C -- Like %c, but the leftmost column is displayed as one.
   %i -- print the size of the buffer.
   %I -- like %i, but use k, M, G, etc., to abbreviate.
   %p -- print percent of buffer above top of window, or Top, Bot or All.
@@ -5629,7 +5632,9 @@ visual lines rather than logical lines.  See the documentation of
   DEFVAR_PER_BUFFER ("default-directory", &BVAR (current_buffer, directory),
                      Qstringp,
                      doc: /* Name of default directory of current buffer.
-To interactively change the default directory, use command `cd'.  */);
+It should be a directory name (as opposed to a directory file-name).
+On GNU and Unix systems, directory names end in a slash `/'.
+To interactively change the default directory, use command `cd'. */);
 
   DEFVAR_PER_BUFFER ("auto-fill-function", &BVAR (current_buffer, auto_fill_function),
                      Qnil,