--- a/src/helper/yans-wifi-helper.h	Wed Jan 27 17:21:36 2010 -0800
+++ b/src/helper/yans-wifi-helper.h	Wed Jan 27 18:41:38 2010 -0800
@@ -135,6 +135,16 @@
  *
  * The Pcap and ascii traces generated by the EnableAscii and EnablePcap methods defined
  * in this class correspond to PHY-level traces. 
+ *
+ * Normally we eschew multiple inheritance, however, the classes 
+ * PcapUserHelperForDevice and AsciiTraceUserHelperForDevice are
+ * treated as "mixins".  A mixin is a self-contained class that
+ * encapsulates a general attribute or a set of functionality that
+ * may be of interest to many other classes.
+ * 
+ * Since the mixins below are self-contained and are explicitly 
+ * designed to avoid naming conflicts through explicit resolution,
+ * multiple inheritance problems are avoided.
  */
 class YansWifiPhyHelper : public WifiPhyHelper, public PcapUserHelperForDevice, public AsciiTraceUserHelperForDevice
 {