Description: Include the Debian-specific egrep, fgrep, rgrep in the man page

Index: grep/doc/grep.in.1
===================================================================
--- grep.orig/doc/grep.in.1
+++ grep/doc/grep.in.1
@@ -137,7 +137,7 @@
 .hy 0
 .
 .SH NAME
-grep \- print lines that match patterns
+grep, egrep, fgrep, rgrep \- print lines that match patterns
 .
 .SH SYNOPSIS
 .B grep
@@ -184,6 +184,23 @@ If no
 .I FILE
 is given, recursive searches examine the working directory,
 and nonrecursive searches read standard input.
+.PP
+Debian also includes the variant programs
+.BR egrep ,
+.B fgrep
+and
+.BR rgrep .
+These programs are the same as
+.BR "grep\ \-E" ,
+.BR "grep\ \-F" ,
+and
+.BR "grep\ \-r" ,
+respectively.
+These variants are deprecated upstream, but Debian provides for backward
+compatibility. For portability reasons, it is recommended to avoid the variant
+programs, and use
+.B grep
+with the related option instead.
 .
 .SH OPTIONS
 .SS "Generic Program Information"