diff --git a/contrib/helper.c b/contrib/helper.c
index 9f9cec7..912fd57 100644
--- a/contrib/helper.c
+++ b/contrib/helper.c
@@ -15,8 +15,8 @@
  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
  *
  *
- * this helper pretty similar to helper.sh, but it
- * doesn't write unrelated variables to file (e.g PWD or PATH)
+ * NOTE: you don't need this if you have mdev/mdevd, refer to mdev.conf
+ * NOTE: you need this if you want to use bare-bones CONFIG_UEVENT_HELPER
  *
  * build:
  * cc helper.c -o helper
diff --git a/contrib/helper.sh b/contrib/helper.sh
index 51bf19f..faa1d61 100644
--- a/contrib/helper.sh
+++ b/contrib/helper.sh
@@ -1,13 +1,10 @@
 #!/bin/sh -f
 #
-# this helper required for CONFIG_UEVENT_HELPER aka /proc/sys/kernel/hotplug
-# for mdev you can use simple one-liner, refer to mdev.conf for more info
+# NOTE: you don't need this if you have mdev/mdevd, refer to mdev.conf
+# NOTE: you need this if you want to use bare-bones CONFIG_UEVENT_HELPER
 #
 # usage:
 # echo /full/path/to/helper.sh > /proc/sys/kernel/hotplug
 # echo "/full/path/to/helper.sh UDEV_MONITOR_DIR" > /proc/sys/kernel/hotplug
-#
 
-# NOTE: writing variables to file (e.g PWD or PATH)
-# that are not related to uevent properties is harmless
 exec env > "${1:-/tmp/.libudev-zero}/uevent.$$"
diff --git a/contrib/mdev.conf b/contrib/mdev.conf
index ff5334c..7bc3c09 100644
--- a/contrib/mdev.conf
+++ b/contrib/mdev.conf
@@ -1,13 +1,12 @@
 #
-# example basic mdev config representing libudev-zero usage 
-# uncomment needed rules
+# example rules for mdev.conf
 #
 # NOTE: you must change "/tmp/.libudev-zero" if you use non-default UDEV_MONITOR_DIR
-# NOTE: mdev can only handle ADD and/or REMOVE events
+# NOTE: you don't need helper.c or helper.sh, just add this to /etc/mdev.conf
 
-# will handle all uevents
+# handle all uevents(not recommended)
 #-.* root:root 660 *env > /tmp/.libudev-zero/uevent.$$
 
-# will handle only drm and input uevents (recommended)
-#SUBSYSTEM=drm;.*   root:video 660 *env > /tmp/.libudev-zero/uevent.$$
-#SUBSYSTEM=input;.* root:input 660 *env > /tmp/.libudev-zero/uevent.$$
+# handle only drm and input uevents(recommended)
+SUBSYSTEM=drm;.*   root:video 660 *env > /tmp/.libudev-zero/uevent.$$
+SUBSYSTEM=input;.* root:input 660 *env > /tmp/.libudev-zero/uevent.$$