--- rxvt-unicode/doc/rxvt.1.pod	2021/07/24 11:00:58	1.255
+++ rxvt-unicode/doc/rxvt.1.pod	2021/11/22 17:00:49	1.256
@@ -535,6 +535,23 @@
    my $slave = $pty->slave;
    while (<$slave>) { print $slave "got <$_>\n" }
 
+Note that, despite what the name might imply, the file descriptor does not
+need to be a pty, it can be a bi-directional pipe as well (e.g. a unix
+domain or tcp socket). While tty operations cannot be done in this case,
+B<@@RXVT_NAME@@> can still be remote controlled with it:
+
+   use Socket;
+   use Fcntl;
+
+   socketpair my $URXVT, my $slave, Socket::AF_UNIX, Socket::SOCK_STREAM, Socket::PF_UNSPEC;
+   fcntl $slave, Fcntl::F_SETFD, 0;
+   system "exec @@RXVT_NAME|| -pty-fd " . (fileno $slave) . " &";
+   close $slave;
+
+   syswrite $URXVT, "Type a secret password: ";
+   my $secret = do { local $/ = "\r"; <$URXVT> };
+   print "No so secret anymore: $secret\n";
+
 =item B<-pe> I<string>
 
 Comma-separated list of perl extension scripts to use (or not to use) in