udevadm monitor -e --udev
monitor will print the received events for:
UDEV - the event which udev sends out after rule processing

UDEV  [1269043396.113802] add      /devices/pci0000:00/0000:00:1d.7/usb1/1-3 (usb)
UDEV_LOG=3
ACTION=add
DEVPATH=/devices/pci0000:00/0000:00:1d.7/usb1/1-3
SUBSYSTEM=usb
DEVNAME=/dev/bus/usb/001/005
DEVTYPE=usb_device
PRODUCT=e21/750/100
TYPE=0/0/0
BUSNUM=001
DEVNUM=005
SEQNUM=1674
ID_VENDOR=COWON_Systems__Inc.
ID_VENDOR_ENC=COWON\x20Systems\x2c\x20Inc.
ID_VENDOR_ID=0e21
ID_MODEL=iAUDIO_7
ID_MODEL_ENC=iAUDIO\x207
ID_MODEL_ID=0750
ID_REVISION=0100
ID_SERIAL=COWON_Systems__Inc._iAUDIO_7_A14270F34CD98D0D
ID_SERIAL_SHORT=A14270F34CD98D0D
ID_BUS=usb
ID_USB_INTERFACES=:080650:
MAJOR=189
MINOR=4
DEVLINKS=/dev/char/189:4

UDEV  [1269043396.116937] add      /devices/pci0000:00/0000:00:1d.7/usb1/1-3/1-3:1.0 (usb)
UDEV_LOG=3
ACTION=add
DEVPATH=/devices/pci0000:00/0000:00:1d.7/usb1/1-3/1-3:1.0
SUBSYSTEM=usb
DEVTYPE=usb_interface
PRODUCT=e21/750/100
TYPE=0/0/0
INTERFACE=8/6/80
MODALIAS=usb:v0E21p0750d0100dc00dsc00dp00ic08isc06ip50
SEQNUM=1675

UDEV  [1269043396.118583] add      /devices/pci0000:00/0000:00:1d.7/usb1/1-3/1-3:1.0/host5 (scsi)
UDEV_LOG=3
ACTION=add
DEVPATH=/devices/pci0000:00/0000:00:1d.7/usb1/1-3/1-3:1.0/host5
SUBSYSTEM=scsi
DEVTYPE=scsi_host
SEQNUM=1676

UDEV  [1269043396.119427] add      /devices/pci0000:00/0000:00:1d.7/usb1/1-3/1-3:1.0/host5/scsi_host/host5 (scsi_host)
UDEV_LOG=3
ACTION=add
DEVPATH=/devices/pci0000:00/0000:00:1d.7/usb1/1-3/1-3:1.0/host5/scsi_host/host5
SUBSYSTEM=scsi_host
SEQNUM=1677

UDEV  [1269043401.123798] add      /devices/pci0000:00/0000:00:1d.7/usb1/1-3/1-3:1.0/host5/target5:0:0 (scsi)
UDEV_LOG=3
ACTION=add
DEVPATH=/devices/pci0000:00/0000:00:1d.7/usb1/1-3/1-3:1.0/host5/target5:0:0
SUBSYSTEM=scsi
DEVTYPE=scsi_target
SEQNUM=1678

UDEV  [1269043401.131531] add      /devices/pci0000:00/0000:00:1d.7/usb1/1-3/1-3:1.0/host5/target5:0:0/5:0:0:0 (scsi)
UDEV_LOG=3
ACTION=add
DEVPATH=/devices/pci0000:00/0000:00:1d.7/usb1/1-3/1-3:1.0/host5/target5:0:0/5:0:0:0
SUBSYSTEM=scsi
DEVTYPE=scsi_device
MODALIAS=scsi:t-0x00
SEQNUM=1679

UDEV  [1269043401.135233] add      /devices/pci0000:00/0000:00:1d.7/usb1/1-3/1-3:1.0/host5/target5:0:0/5:0:0:0/scsi_device/5:0:0:0 (scsi_device)
UDEV_LOG=3
ACTION=add
DEVPATH=/devices/pci0000:00/0000:00:1d.7/usb1/1-3/1-3:1.0/host5/target5:0:0/5:0:0:0/scsi_device/5:0:0:0
SUBSYSTEM=scsi_device
SEQNUM=1681

UDEV  [1269043401.135288] add      /devices/pci0000:00/0000:00:1d.7/usb1/1-3/1-3:1.0/host5/target5:0:0/5:0:0:0/scsi_disk/5:0:0:0 (scsi_disk)
UDEV_LOG=3
ACTION=add
DEVPATH=/devices/pci0000:00/0000:00:1d.7/usb1/1-3/1-3:1.0/host5/target5:0:0/5:0:0:0/scsi_disk/5:0:0:0
SUBSYSTEM=scsi_disk
SEQNUM=1680

UDEV  [1269043401.140110] add      /devices/pci0000:00/0000:00:1d.7/usb1/1-3/1-3:1.0/host5/target5:0:0/5:0:0:0/scsi_generic/sg2 (scsi_generic)
UDEV_LOG=3
ACTION=add
DEVPATH=/devices/pci0000:00/0000:00:1d.7/usb1/1-3/1-3:1.0/host5/target5:0:0/5:0:0:0/scsi_generic/sg2
SUBSYSTEM=scsi_generic
DEVNAME=/dev/sg2
SEQNUM=1682
MAJOR=21
MINOR=2
DEVLINKS=/dev/char/21:2

UDEV  [1269043401.141419] change   /devices/pci0000:00/0000:00:1d.7/usb1/1-3/1-3:1.0/host5/target5:0:0/5:0:0:0 (scsi)
UDEV_LOG=3
ACTION=change
DEVPATH=/devices/pci0000:00/0000:00:1d.7/usb1/1-3/1-3:1.0/host5/target5:0:0/5:0:0:0
SUBSYSTEM=scsi
SDEV_MEDIA_CHANGE=1
DEVTYPE=scsi_device
DRIVER=sd
MODALIAS=scsi:t-0x00
SEQNUM=1683

UDEV  [1269043401.144433] add      /devices/virtual/bdi/8:16 (bdi)
UDEV_LOG=3
ACTION=add
DEVPATH=/devices/virtual/bdi/8:16
SUBSYSTEM=bdi
SEQNUM=1685

UDEV  [1269043401.210877] add      /devices/pci0000:00/0000:00:1d.7/usb1/1-3/1-3:1.0/host5/target5:0:0/5:0:0:0/block/sdb (block)
UDEV_LOG=3
ACTION=add
DEVPATH=/devices/pci0000:00/0000:00:1d.7/usb1/1-3/1-3:1.0/host5/target5:0:0/5:0:0:0/block/sdb
SUBSYSTEM=block
DEVNAME=/dev/sdb
DEVTYPE=disk
SEQNUM=1684
ID_VENDOR=COWON
ID_VENDOR_ENC=COWON\x20\x20\x20
ID_VENDOR_ID=0e21
ID_MODEL=iAUDIO_7
ID_MODEL_ENC=iAUDIO\x207\x20\x20\x20\x20\x20\x20\x20\x20
ID_MODEL_ID=0750
ID_REVISION=0100
ID_SERIAL=COWON_iAUDIO_7_A14270F34CD98D0D-0:0
ID_SERIAL_SHORT=A14270F34CD98D0D
ID_TYPE=disk
ID_INSTANCE=0:0
ID_BUS=usb
ID_USB_INTERFACES=:080650:
ID_USB_INTERFACE_NUM=00
ID_USB_DRIVER=usb-storage
ID_PATH=pci-0000:00:1d.7-usb-0:3:1.0-scsi-0:0:0:0
ID_FS_LABEL=I_AUDIO7
ID_FS_LABEL_ENC=I\x20AUDIO7
ID_FS_UUID=7CB0-6ED8
ID_FS_UUID_ENC=7CB0-6ED8
ID_FS_VERSION=FAT32
ID_FS_TYPE=vfat
ID_FS_USAGE=filesystem
UDISKS_PRESENTATION_NOPOLICY=0
ID_MEDIA_PLAYER=cowon-0510_0520_0710_0730_0750
MAJOR=8
MINOR=16
DEVLINKS=/dev/block/8:16 /dev/disk/by-id/usb-COWON_iAUDIO_7_A14270F34CD98D0D-0:0 /dev/disk/by-path/pci-0000:00:1d.7-usb-0:3:1.0-scsi-0:0:0:0 /dev/disk/by-uuid/7CB0-6ED8 /dev/disk/by-label/I\x20AUDIO7