diff --git a/51-android.rules b/51-android.rules
index 5f0992a..5c98422 100644
--- a/51-android.rules
+++ b/51-android.rules
@@ -15,28 +15,29 @@
 # You should have received a copy of the GNU General Public License
 # along with this program. If not, see <http://www.gnu.org/licenses/>.
 
-# Skip this section below if this device is not connected by USB
+# Skip testing for android devices if device is not add, or usb
 ACTION!="add", GOTO="android_usb_rules_end"
 SUBSYSTEM!="usb", GOTO="android_usb_rules_end"
 
-# This is the universal rule suggested here:
+# For Android devices that enable this universal rule suggested here:
 # http://ktnr74.blogspot.com/2013/04/universal-udev-rule-for-all-android.html
 # Commented as a reminder (we prefer a punctual device detection)
-# LABEL="android_universal_rule"
-# ENV{ID_USB_INTERFACES}!="*:ff420?:*", GOTO="android_usb_rules_begin"
-# ACTION=="add", SUBSYSTEM=="usb", ENV{DEVTYPE}=="usb_device", ENV{ID_USB_INTERFACES}=="*:ff420?:*", MODE="0660", GROUP="adbusers", SYMLINK+="android/$env{ID_SERIAL_SHORT}"
+# ENV{ID_USB_INTERFACES}=="*:ff420?:*", SYMLINK+="android/$env{ID_SERIAL_SHORT}", GOTO="android_usb_rule_match"
+
+# Skip testing for unexpected devices like hubs or printers
+ATTR{bDeviceClass}=="09", GOTO="android_usb_rules_end"
+ENV{ID_USB_INTERFACES}=="*:0701??:*", ENV{adb_adb}="yes", GOTO="android_usb_rules_end"
 
 LABEL="android_usb_rules_begin"
 # Devices listed here in android_usb_rules_{begin...end} are connected by USB
 #	Acer
 ATTR{idVendor}!="0502", GOTO="not_Acer"
-ENV{adb_user}="yes"
 #		Iconia Tab A1-830
 ATTR{idProduct}=="3604", ENV{adb_adbfast}="yes"
 #		Iconia Tab A500
 ATTR{idProduct}=="3325", ENV{adb_adbfast}="yes"
 #		Liquid (3202=normal,3203=debug)
-ATTR{idProduct}=="3203", SYMLINK+="android_adb"
+ATTR{idProduct}=="3203", ENV{adb_user}="yes"
 GOTO="android_usb_rule_match"
 LABEL="not_Acer"
 
@@ -54,7 +55,6 @@ ATTR{idVendor}=="1949", ATTR{idProduct}=="0006", ENV{adb_adbfast}="yes"
 
 #	Archos
 ATTR{idVendor}!="0e79", GOTO="not_Archos"
-ENV{adb_user}="yes"
 #		43
 ATTR{idProduct}=="1417", ENV{adb_adbfast}="yes"
 #		101
@@ -93,7 +93,6 @@ ATTR{idVendor}=="1f3a", ENV{adb_user}="yes"
 
 #	BQ
 ATTR{idVendor}!="2a47", GOTO="not_BQ"
-ENV{adb_user}="yes"
 #		Aquaris 4.5
 ATTR{idProduct}=="0c02", ENV{adb_adbfast}="yes"
 ATTR{idProduct}=="2008", ENV{adb_adbfast}="yes"
@@ -105,10 +104,9 @@ LABEL="not_BQ"
 
 #	Essential
 ATTR{idVendor}!="2e17", GOTO="not_Essential"
-ENV{adb_user}="yes"
 #		Essential PH-1
-ATTR{idProduct}=="c009", SYMLINK+="android_adb"
-ATTR{idProduct}=="c03[02]", SYMLINK+="android_adb"
+ATTR{idProduct}=="c009", ENV{adb_adb}=="yes"
+ATTR{idProduct}=="c03[02]", ENV{adb_adb}=="yes"
 GOTO="android_usb_rule_match"
 LABEL="not_Essential"
 
@@ -133,41 +131,39 @@ ATTR{idVendor}=="091e", ENV{adb_user}="yes"
 
 #	Google
 ATTR{idVendor}!="18d1", GOTO="not_Google"
-ENV{adb_user}="yes"
 #		Nexus, Pixel, Pixel XL, Pixel 2, Pixel 2XL (4ee2=mtp,adb 4ee4=rndis,adb 4ee6=ptp,adb 4ee7=adb 4ee9=midi,adb 2d01=accessory,adb 2d03=audio_source,adb 2d05=accessory,audio_source,adb)
 #		See https://android.googlesource.com/device/google/wahoo/+/master/init.hardware.usb.rc
-ATTR{idProduct}=="4ee2", SYMLINK+="android_adb"
-ATTR{idProduct}=="4ee4", SYMLINK+="android_adb"
-ATTR{idProduct}=="4ee6", SYMLINK+="android_adb"
-ATTR{idProduct}=="4ee7", SYMLINK+="android_adb"
-ATTR{idProduct}=="4ee9", SYMLINK+="android_adb"
-ATTR{idProduct}=="2d01", SYMLINK+="android_adb"
-ATTR{idProduct}=="2d03", SYMLINK+="android_adb"
-ATTR{idProduct}=="2d05", SYMLINK+="android_adb"
-ATTR{idProduct}=="4ee0", SYMLINK+="android_fastboot"
+#		OnePlus 6, 4ee1=charging, 4ee2=MTP+debug, 4ee6=PTP+debug, 4ee7=charging+debug
+# 		Pico i.MX7 Dual Development Board 4ee7=debug
+ATTR{idProduct}=="4ee0", ENV{adb_adbfast}="yes"
+ATTR{idProduct}=="4ee2", ENV{adb_adb}="yes"
+ATTR{idProduct}=="4ee4", ENV{adb_adb}="yes"
+ATTR{idProduct}=="4ee6", ENV{adb_adb}="yes"
+ATTR{idProduct}=="4ee7", ENV{adb_adb}="yes"
+ATTR{idProduct}=="4ee9", ENV{adb_adb}="yes"
+
+ATTR{idProduct}=="2d01", ENV{adb_adb}="yes"
+ATTR{idProduct}=="2d03", ENV{adb_adb}="yes"
+ATTR{idProduct}=="2d05", ENV{adb_adb}="yes"
 #		Nexus 7
-ATTR{idProduct}=="4e42", SYMLINK+="android_adb"
-ATTR{idProduct}=="4e40", SYMLINK+="android_fastboot"
+ATTR{idProduct}=="4e42", ENV{adb_adb}="yes"
+ATTR{idProduct}=="4e40", ENV{adb_adbfast}="yes"
 #		Nexus 5, Nexus 10
 ATTR{idProduct}=="4ee1", ENV{adb_adbfast}="yes"
 #		Nexus S (4e22=mass_storage,adb 4e24=rndis,adb)
 #		See https://android.googlesource.com/device/samsung/crespo/+/android-4.1.2_r2.1/init.herring.usb.rc
-ATTR{idProduct}=="4e22", SYMLINK+="android_adb"
-ATTR{idProduct}=="4e24", SYMLINK+="android_adb"
-ATTR{idProduct}=="4e20", SYMLINK+="android_fastboot"
-#		Galaxy Nexus
+ATTR{idProduct}=="4e22", ENV{adb_adb}="yes"
+ATTR{idProduct}=="4e24", ENV{adb_adb}="yes"
+ATTR{idProduct}=="4e20", ENV{adb_adbfast}="yes"
+#		Galaxy Nexus, Galaxy Nexus (GSM)
 ATTR{idProduct}=="4e30", ENV{adb_adbfast}="yes"
 #		Nexus One (4e11=normal,4e12=debug,0fff=debug)
-ATTR{idProduct}=="4e12", SYMLINK+="android_adb"
-ATTR{idProduct}=="0fff", SYMLINK+="android_fastboot"
-#		Generic and unspecified debug interface
-ATTR{idProduct}=="d00d", SYMLINK+="android_fastboot"
-# 		Pico i.MX7 Dual Development Board
-ATTR{idProduct}=="4ee7", SYMLINK+="android_adb"
-#		Include: Samsung Galaxy Nexus (GSM)
-ATTR{idProduct}=="4e30", SYMLINK+="android_fastboot"
+ATTR{idProduct}=="4e12", ENV{adb_adb}="yes"
+ATTR{idProduct}=="0fff", ENV{adb_adbfast}="yes"
 #		Recovery adb entry for Nexus Family (orig d001, OP3 has 18d1:d002)
-ATTR{idProduct}=="d00?", SYMLINK+="android_adb"
+ATTR{idProduct}=="d00?", ENV{adb_adb}="yes"
+#		Generic and unspecified debug interface (test after d00?)
+ATTR{idProduct}=="d00d", ENV{adb_adbfast}="yes"
 GOTO="android_usb_rule_match"
 LABEL="not_Google"
 
@@ -179,9 +175,8 @@ ATTR{idVendor}=="109b", ENV{adb_user}="yes"
 
 #	Honeywell/Foxconn
 ATTR{idVendor}!="0c2e", GOTO="not_Honeywell"
-ENV{adb_user}="yes"
 #		D70e
-ATTR{idProduct}=="0ba3", SYMLINK+="android_adb"
+ATTR{idProduct}=="0ba3", ENV{adb_adb}=="yes"
 GOTO="android_usb_rule_match"
 LABEL="not_Honeywell"
 
@@ -282,9 +277,8 @@ LABEL="not_Intel"
 
 #	IUNI
 ATTR{idVendor}!="271d", GOTO="not_IUNI"
-ENV{adb_user}="yes"
 #		U3
-ATTR{idProduct}=="bf39", SYMLINK+="android_adb"
+ATTR{idProduct}=="bf39", ENV{adb_adb}=="yes"
 GOTO="android_usb_rule_match"
 LABEL="not_IUNI"
 
@@ -341,25 +335,22 @@ LABEL="not_LG"
 
 #       Idea
 ATTR{idVendor}!="18d1", GOTO="not_IDEA"
-ENV{adb_user}="yes"
 #       XDS-1078
-ATTR{idProduct}=="2c11", SYMLINK="android_adb"
+ATTR{idProduct}=="2c11", ENV{adb_adb}=="yes"
 GOTO="android_usb_rule_match"
 LABEL="not_IDEA"
 
 #	Meizu
 ATTR{idVendor}!="2a45", GOTO="not_Meizu"
-ENV{adb_user}="yes"
 #		MX6
-ATTR{idProduct}=="0c02", SYMLINK+="android_adb"
+ATTR{idProduct}=="0c02", ENV{adb_adb}=="yes"
 GOTO="android_usb_rule_match"
 LABEL="not_Meizu"
 
 #	Micromax
 ATTR{idVendor}!="2a96", GOTO="not_Micromax"
-ENV{adb_user}="yes"
 #		P702
-ATTR{idProduct}=="201d", SYMLINK+="android_adb", SYMLINK+="android_fastboot"
+ATTR{idProduct}=="201d", ENV{adb_adbfast}=="yes"
 GOTO="android_usb_rule_match"
 LABEL="not_Micromax"
 
@@ -430,19 +421,19 @@ ATTR{idVendor}=="2833", ENV{adb_user}="yes"
 
 #	OnePlus(Oreo)
 ATTR{idVendor}!="2a70", GOTO="not_OnePlus"
-ENV{adb_user}="yes"
-#		Charging mode
-ATTR{idProduct}=="4ee7", SYMLINK+="android_adb"
+#		OnePlus 6, 4ee1=charging, 4ee2=MTP+debug, 4ee6=PTP+debug, 4ee7=charging+debug
+ATTR{idProduct}=="4ee2", ENV{adb_adb}="yes"
+ATTR{idProduct}=="4ee6", ENV{adb_adb}="yes"
+ATTR{idProduct}=="4ee7", ENV{adb_adb}="yes"
 #		MTP mode
-ATTR{idProduct}=="9011", SYMLINK+="android_adb"
+ATTR{idProduct}=="9011", ENV{adb_adb}="yes"
 #		PTP mode
-ATTR{idProduct}=="904e", SYMLINK+="android_adb"
+ATTR{idProduct}=="904e", ENV{adb_adb}="yes"
 GOTO="android_usb_rule_match"
 LABEL="not_OnePlus"
 
 #	Oppo
 ATTR{idVendor}!="22d9", GOTO="not_Oppo"
-ENV{adb_adbuser}="yes"
 #		Find 5 (2767=debug)
 ATTR{idProduct}=="2767", ENV{adb_adb}="yes"
 ATTR{idProduct}=="2764", SYMLINK+="libmtp-%k", ENV{ID_MTP_DEVICE}="1", ENV{ID_MEDIA_PLAYER}="1"
@@ -496,7 +487,6 @@ LABEL="not_Qualcomm"
 
 #	Research In Motion, Ltd.
 ATTR{idVendor}!="0fca", GOTO="not_RIM"
-ENV{adb_user}="yes"
 #		BlackBerry DTEK60
 ATTR{idProduct}=="8042", ENV{adb_fastboot}="yes"
 GOTO="android_usb_rule_match"
@@ -664,7 +654,6 @@ ATTR{idVendor}=="1ebf", ENV{adb_user}="yes"
 
 #	Zebra
 ATTR{idVendor}!="05e0", GOTO="not_Zebra"
-ENV{adb_user}="yes"
 #		TC55
 ATTR{idProduct}=="2101", ENV{adb_adb}="yes"
 GOTO="android_usb_rule_match"
@@ -672,11 +661,10 @@ LABEL="not_Zebra"
 
 #	ZTE
 ATTR{idVendor}!="19d2", GOTO="not_ZTE"
-ENV{adb_user}="yes"
 #		Blade (1353=normal,1351=debug)
-ATTR{idProduct}=="1351", SYMLINK+="android_adb"
+ATTR{idProduct}=="1351", ENV{adb_adb}="yes"
 #		Blade S (Crescent, Orange San Francisco 2) (1355=normal,1354=debug)
-ATTR{idProduct}=="1354", SYMLINK+="android_adb"
+ATTR{idProduct}=="1354", ENV{adb_adb}="yes"
 GOTO="android_usb_rule_match"
 LABEL="not_ZTE"