Index: head/sysutils/unetbootin/pkg-message
===================================================================
--- head/sysutils/unetbootin/pkg-message	(revision 524175)
+++ head/sysutils/unetbootin/pkg-message	(revision 524176)
@@ -1,9 +1,12 @@
 [
 { type: install
   message: <<EOM
+    UNetbootin requires *mounted* MSDOSFS (FAT) filesystem to work against,
+    it will not mount your USB memstick or SD card for you!
+
     If SysLinux refuses to boot with a "Boot error" message when written to
     a PC partition (slice), try to reformat the drive in raw (or dedicated)
     mode (that is, without a partition table), then reinstall things again.
 EOM
 }
 ]