+Match the subsystem of the event device.
+.TP 3n
+\fBATTR{\fR\fB\fIfilename\fR\fR\fB}\fR
+Match sysfs attribute values of the event device. Up to five
+\fBATTR\fR
+keys can be specified per rule. Trailing whitespace in the attribute values is ignored, if the specified match value does not contain trailing whitespace itself.