sh-5.0#udevadm monitor -p -s bluetooth
monitor will print the received events for:
UDEV - the event which udev sends out after rule processing
KERNEL - the kernel uevent

KERNEL[850.727003] remove   /devices/virtual/bluetooth/hci0 (bluetooth)
ACTION=remove
DEVPATH=/devices/virtual/bluetooth/hci0
DEVTYPE=host
SEQNUM=4037
SUBSYSTEM=bluetooth

UDEV  [850.752165] remove   /devices/virtual/bluetooth/hci0 (bluetooth)
ACTION=remove
DEVPATH=/devices/virtual/bluetooth/hci0
DEVTYPE=host
SEQNUM=4037
SUBSYSTEM=bluetooth
SYSTEMD_ALIAS=/sys/subsystem/bluetooth/devices/hci0
SYSTEMD_WANTS=bluetooth.target
TAGS=:systemd:
USEC_INITIALIZED=23118747

KERNEL[852.658447] add      /devices/virtual/bluetooth/hci0 (bluetooth)
ACTION=add
DEVPATH=/devices/virtual/bluetooth/hci0
DEVTYPE=host
SEQNUM=4075
SUBSYSTEM=bluetooth

UDEV  [852.672975] add      /devices/virtual/bluetooth/hci0 (bluetooth)
ACTION=add
DEVPATH=/devices/virtual/bluetooth/hci0
DEVTYPE=host
SEQNUM=4075
SUBSYSTEM=bluetooth
SYSTEMD_ALIAS=/sys/subsystem/bluetooth/devices/hci0
SYSTEMD_WANTS=bluetooth.target
TAGS=:systemd:
USEC_INITIALIZED=852670788

KERNEL[879.562261] remove   /devices/virtual/bluetooth/hci0 (bluetooth)
ACTION=remove
DEVPATH=/devices/virtual/bluetooth/hci0
DEVTYPE=host
SEQNUM=4130
SUBSYSTEM=bluetooth

UDEV  [879.570036] remove   /devices/virtual/bluetooth/hci0 (bluetooth)
ACTION=remove
DEVPATH=/devices/virtual/bluetooth/hci0
DEVTYPE=host
SEQNUM=4130
SUBSYSTEM=bluetooth
SYSTEMD_ALIAS=/sys/subsystem/bluetooth/devices/hci0
SYSTEMD_WANTS=bluetooth.target
TAGS=:systemd:
USEC_INITIALIZED=852670788

KERNEL[881.174653] add      /devices/virtual/bluetooth/hci0 (bluetooth)
ACTION=add
DEVPATH=/devices/virtual/bluetooth/hci0
DEVTYPE=host
SEQNUM=4180
SUBSYSTEM=bluetooth

UDEV  [881.179019] add      /devices/virtual/bluetooth/hci0 (bluetooth)
ACTION=add
DEVPATH=/devices/virtual/bluetooth/hci0
DEVTYPE=host
SEQNUM=4180
SUBSYSTEM=bluetooth
SYSTEMD_ALIAS=/sys/subsystem/bluetooth/devices/hci0
SYSTEMD_WANTS=bluetooth.target
TAGS=:systemd:
USEC_INITIALIZED=881178501