Index: x11-servers/xorg-server/pkg-message
===================================================================
--- x11-servers/xorg-server/pkg-message	(revision 537615)
+++ x11-servers/xorg-server/pkg-message	(working copy)
@@ -20,6 +20,16 @@
 To make it persistent across reboots, add the following to /etc/sysctl.conf:
 
 kern.evdev.rcpt_mask=6
+
+In case you're using a serial mouse or any other mouse that works over
+sysmouse(4) and moused(8) on an evdev enabled kernel, please run this:
+
+# sysctl kern.evdev.rcpt_mask=3
+
+To make it persistent across reboots, add to this /etc/sysctl.conf:
+
+kern.evdev.rcpt_mask=3
+
 EOM
 }
 ]