diff --git a/libexec/comsat/comsat.8 b/libexec/comsat/comsat.8
index 0b660352cd70..dd1c47de6f48 100644
--- a/libexec/comsat/comsat.8
+++ b/libexec/comsat/comsat.8
@@ -76,6 +76,13 @@ or
 .Dq Subject
 lines are not included in the displayed message.
 .Pp
+If the
+.Em user
+specified is logged in to the system and the associated terminal has
+the group execute bit turned on (by a
+.Dq Li biff b ) ,
+two bell characters (ASCII \\007) are printed on the user's terminal.
+.Pp
 If mailbox-name omitted, standard mailbox assumed.
 .Sh FILES
 .Bl -tag -width /var/mail/user -compact
diff --git a/libexec/comsat/comsat.c b/libexec/comsat/comsat.c
index a966002f28af..1221566c7736 100644
--- a/libexec/comsat/comsat.c
+++ b/libexec/comsat/comsat.c
@@ -211,7 +211,7 @@ notify(struct utmp *utp, char file[], off_t offset, int folder)
 		syslog(LOG_AUTH | LOG_NOTICE, "'/' in \"%s\"", tty);
 		return;
 	}
-	if (stat(tty, &stb) || !(stb.st_mode & S_IEXEC)) {
+	if (stat(tty, &stb) || !(stb.st_mode & (S_IXUSR | S_IXGRP))) {
 		dsyslog(LOG_DEBUG, "%s: wrong mode on %s", utp->ut_name, tty);
 		return;
 	}
@@ -228,11 +228,25 @@ notify(struct utmp *utp, char file[], off_t offset, int folder)
 	cr = ((tio.c_oflag & (OPOST|ONLCR)) == (OPOST|ONLCR)) ?  "\n" : "\n\r";
 	(void)strncpy(name, utp->ut_name, sizeof(utp->ut_name));
 	name[sizeof(name) - 1] = '\0';
-	(void)fprintf(tp, "%s\007New mail for %s@%.*s\007 has arrived%s%s%s:%s----%s",
-	    cr, name, (int)sizeof(hostname), hostname,
-	    folder ? cr : "", folder ? "to " : "", folder ? file : "",
-	    cr, cr);
-	jkfprintf(tp, name, file, offset);
+	switch (stb.st_mode & (S_IXUSR | S_IXGRP)) {
+	case S_IXUSR:
+	case (S_IXUSR | S_IXGRP):
+		(void)fprintf(tp, 
+		    "%s\007New mail for %s@%.*s\007 has arrived%s%s%s:%s----%s",
+		    cr, name, (int)sizeof(hostname), hostname,
+		    folder ? cr : "", folder ? "to " : "", folder ? file : "",
+		    cr, cr);
+		jkfprintf(tp, name, file, offset);
+		break;
+	case S_IXGRP:
+		(void)fprintf(tp, "\007");
+		(void)fflush(tp);      
+		(void)sleep(1);
+		(void)fprintf(tp, "\007");
+		break;
+	default:
+		break;
+	}	
 	(void)fclose(tp);
 	_exit(0);
 }
diff --git a/usr.bin/biff/biff.1 b/usr.bin/biff/biff.1
index c19a0b182279..49d711d668df 100644
--- a/usr.bin/biff/biff.1
+++ b/usr.bin/biff/biff.1
@@ -40,7 +40,7 @@
 .Nd "be notified if mail arrives and who it is from"
 .Sh SYNOPSIS
 .Nm
-.Op Cm n | y
+.Op Cm n | y | b
 .Sh DESCRIPTION
 The
 .Nm
@@ -52,11 +52,13 @@ The following options are available:
 .It Cm n
 Disable notification.
 .It Cm y
-Enable notification.
+Enable header notification.
+.It Cm b
+Enable bell notification.
 .El
 .Pp
-When mail notification is enabled, the header and first few lines of
-the message will be printed on your screen whenever mail arrives.
+When header notification is enabled, the header and first few lines of
+the message will be printed on your terminal whenever mail arrives.
 A
 .Dq Li biff y
 command is often included in the file
@@ -65,6 +67,9 @@ or
 .Pa \&.profile
 to be executed at each login.
 .Pp
+When bell notification is enabled, only two bell characters (ASCII \\007) 
+will be printed on your terminal whenever mail arrives.
+.Pp
 The
 .Nm
 utility operates asynchronously.
diff --git a/usr.bin/biff/biff.c b/usr.bin/biff/biff.c
index 67341bac8ee9..ccbc32ab6c9a 100644
--- a/usr.bin/biff/biff.c
+++ b/usr.bin/biff/biff.c
@@ -81,28 +81,35 @@ main(argc, argv)
 		err(2, "stat");
 
 	if (*argv == NULL) {
-		(void)printf("is %s\n", sb.st_mode & S_IXUSR ? "y" : "n");
-		return(sb.st_mode & S_IXUSR ? 0 : 1);
+		(void)printf("is %s%s\n",
+		    sb.st_mode & S_IXUSR ? "y" :
+		    sb.st_mode & S_IXGRP ? "b" : "n");
+		return(sb.st_mode & (S_IXUSR | S_IXGRP) ? 0 : 1);
+
 	}
 
 	switch(argv[0][0]) {
 	case 'n':
-		if (chmod(name, sb.st_mode & ~S_IXUSR) < 0)
+		if (chmod(name, sb.st_mode & ~(S_IXUSR | S_IXGRP)) < 0)
 			err(2, "%s", name);
 		break;
 	case 'y':
-		if (chmod(name, sb.st_mode | S_IXUSR) < 0)
+		if (chmod(name, (sb.st_mode & ~(S_IXUSR | S_IXGRP)) | S_IXUSR) < 0)
+			err(2, "%s", name);
+		break;
+	case 'b':
+		if (chmod(name, (sb.st_mode & ~(S_IXUSR | S_IXGRP)) | S_IXGRP) < 0)
 			err(2, "%s", name);
 		break;
 	default:
 		usage();
 	}
-	return(sb.st_mode & S_IXUSR ? 0 : 1);
+	return(sb.st_mode & (S_IXUSR | S_IXGRP) ? 0 : 1);
 }
 
 static void
 usage()
 {
-	(void)fprintf(stderr, "usage: biff [y | n]\n");
+	(void)fprintf(stderr, "usage: biff [n | y | b]\n");
 	exit(2);
 }