Thanks for reporting that -- it has been a bug in the manual for sixteen years!
I installed the attached patch.
From d124dbfde656a0aee00d5d89406acdb0c5bfe831 Mon Sep 17 00:00:00 2001
From: Paul Eggert <egg...@cs.ucla.edu>
Date: Thu, 17 Sep 2015 00:37:30 -0700
Subject: [PATCH] =?UTF-8?q?shred:=20don=E2=80=99t=20document=20-NUMBER=20o?=
=?UTF-8?q?ption?=
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The -NUMBER option was removed from ‘shred’ in 1999, but the
manual wasn’t updated to match. Problem reported by Nick Rose in:
http://bugs.gnu.org/21502
* doc/coreutils.texi (shred invocation):
Remove documentation for -NUMBER option.
---
doc/coreutils.texi | 3 +--
1 file changed, 1 insertion(+), 2 deletions(-)
diff --git a/doc/coreutils.texi b/doc/coreutils.texi
index 5589162..a029ec6 100644
--- a/doc/coreutils.texi
+++ b/doc/coreutils.texi
@@ -9396,8 +9396,7 @@ The program accepts the following options. Also see
@ref{Common options}.
@cindex force deletion
Override file permissions if necessary to allow overwriting.
-@item -@var{number}
-@itemx -n @var{number}
+@item -n @var{number}
@itemx --iterations=@var{number}
@opindex -n @var{number}
@opindex --iterations=@var{number}
--
2.1.0
