1 files changed, 6 insertions, 2 deletions

diff --git a/src/editfns.c b/src/editfns.c
index e3a7d1f7fa1..6aba319d5b2 100644
--- a/src/editfns.c
+++ b/src/editfns.c
@@ -194,8 +194,12 @@ DEFUN ("byte-to-string", Fbyte_to_string, Sbyte_to_string, 1, 1, 0,
 }
 
 DEFUN ("string-to-char", Fstring_to_char, Sstring_to_char, 1, 1, 0,
-       doc: /* Convert arg STRING to a character, the first character of that string.
-A multibyte character is handled correctly.  */)
+       doc: /* Return the first character in STRING.
+A multibyte character is handled correctly.
+The value returned is a Unicode codepoint if it is below #x110000 (in
+hex).  Codepoints beyond that are Emacs extensions of Unicode.  In
+particular, eight-bit characters are returned as codepoints in the
+range #x3FFF80 through #x3FFFFF, inclusive.  */)
   (register Lisp_Object string)
 {
   register Lisp_Object val;