-Every line defines the mapping between device attributes and the device file
-name. It starts with a keyword defining the method used to match, followed by
-one ore more keys to compare and the filename for the device. If no matching
-configuration is found, the default kernel device name is used.
+.P
+.RI "A sample " udev.conf " might look like this:
+.sp
+.nf
+# udev_root - where in the filesystem to place the device nodes
+udev_root="/udev/"
+
+# udev_db - The name and location of the udev database.
+udev_db="/udev/.udev.tdb"
+
+# udev_rules - The name and location of the udev rules file
+udev_rules="/etc/udev/udev.rules"
+
+# udev_permissions - The name and location of the udev permission file
+udev_permissions="/etc/udev/udev.permissions"
+
+# udev_log - set to "yes" if you want logging, else "no"
+udev_log="yes"
+
+# default_mode - set the default mode for all nodes that have no
+# explicit match in the permissions file
+default_mode="0666"
+
+# default_owner - set the default owner for all nodes that have no
+# explicit match in the permissions file
+default_owner="root"
+
+# default_group - set the default group for all nodes that have no
+# explicit match in the permissions file
+default_group="root"
+.fi
+.P
+The rules for udev to use when naming devices may specified at
+.I /etc/udev/udev.rules
+or specified by the
+.I udev_rules
+value in the
+.I /etc/udev/udev.conf
+file.
+.P
+Every line in the rules file defines the mapping between device attributes
+and the device file name. One ore more keys are specified to match a rule
+with the current device. If all keys are matching, the rule will be applied
+and the name is used for the device node. One or more optional symlinks
+targeting the node may be specified.
+.br
+If no matching rule is found, the default kernel device name is used.