-.\" Copyright (c) 1989 The Regents of the University of California.
-.\" All rights reserved.
+.\" $NetBSD: caesar.6,v 1.6 1997/11/12 00:48:29 mrg Exp $
+.\"
+.\" Copyright (c) 1989, 1991, 1993
+.\" The Regents of the University of California. All rights reserved.
.\"
.\" Redistribution and use in source and binary forms, with or without
.\" modification, are permitted provided that the following conditions
.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
.\" SUCH DAMAGE.
.\"
-.\" from: @(#)caesar.6 5.3 (Berkeley) 11/11/90
-.\" $Id: caesar.6,v 1.2 1993/08/01 07:47:21 mycroft Exp $
+.\" @(#)caesar.6 8.2 (Berkeley) 11/16/93
.\"
-.TH CAESAR 6 "November 11, 1990"
-.UC 7
-.SH NAME
-caesar \- decrypt caesar cyphers
-.SH SYNOPSIS
-.B caesar
-[
-.B rotation
-]
-.SH DESCRIPTION
+.Dd November 16, 1993
+.Dt CAESAR 6
+.Os
+.Sh NAME
+.Nm caesar ,
+.Nm rot13
+.Nd decrypt caesar cyphers
+.Sh SYNOPSIS
+.Nm
+.Op Ar rotation
+.Sh DESCRIPTION
The
-.I caesar
+.Nm
utility attempts to decrypt caesar cyphers using English letter frequency
statistics.
-.I Caesar
+.Nm
reads from the standard input and writes to the standard output.
-.PP
+.Pp
The optional numerical argument
-.I rotation
+.Ar rotation
may be used to specify a specific rotation value.
-.PP
+.Pp
The frequency (from most common to least) of English letters is as follows:
-.sp
-.RS
+.Pp
+.Bd -filled -offset indent
ETAONRISHDLFCMUGPYWBVKXJQZ
-.RE
-.PP
+.Ed
+.Pp
Their frequencies as a percentage are as follows:
-.sp
-.RS
+.Pp
+.Bd -filled -offset indent
E(13), T(10.5), A(8.1), O(7.9), N(7.1), R(6.8), I(6.3), S(6.1), H(5.2),
-D(3.8), L(3.4), F(2.9), C(2.7), M(2.5), U(2.4), G(2), P(1.9), Y(1.9),
+D(3.8), L(3.4), F(2.9), C(2.7), M(2.5), U(2.4), G(2),
+P(1.9), Y(1.9),
W(1.5), B(1.4), V(.9), K(.4), X(.15), J(.13), Q(.11), Z(.07).
-.RE
-.PP
-Rotated postings to USENET and some of the databases used by the
-.IR fortune (6)
+.Ed
+.Pp
+Rotated postings to
+.Tn USENET
+and some of the databases used by the
+.Xr fortune 6
program are rotated by 13 characters.