diff --git a/include/boost/multi_index/composite_key.hpp b/include/boost/multi_index/composite_key.hpp
index 2ea6c87..66042d6 100644
--- a/include/boost/multi_index/composite_key.hpp
+++ b/include/boost/multi_index/composite_key.hpp
@@ -531,6 +531,16 @@ struct composite_key_result
 
 /* composite_key */
 
+/* NB. Some overloads of operator() have an extra dummy parameter int=0.
+ * This disambiguator serves several purposes:
+ *  - Without it, MSVC++ 6.0 incorrectly regards some overloads as
+ *    specializations of a previous member function template.
+ *  - MSVC++ 6.0/7.0 seem to incorrectly treat some different memfuns
+ *    as if they have the same signature.
+ *  - If remove_const is broken due to lack of PTS, int=0 avoids the
+ *    declaration of memfuns with identical signature.
+ */
+
 template<
   typename Value,
   BOOST_MULTI_INDEX_CK_ENUM(BOOST_MULTI_INDEX_CK_TEMPLATE_PARM,KeyFromValue)
diff --git a/include/boost/multi_index/identity.hpp b/include/boost/multi_index/identity.hpp
index 6a375b8..509ac68 100644
--- a/include/boost/multi_index/identity.hpp
+++ b/include/boost/multi_index/identity.hpp
@@ -34,9 +34,13 @@ namespace detail{
  */
 
 /* NB. Some overloads of operator() have an extra dummy parameter int=0.
- * This is so because MSVC++ 6.0 otherwise *incorrectly* regards these
- * overloads as specializations of a previous member function template.
- * Left for all compilers as it does no harm.
+ * This disambiguator serves several purposes:
+ *  - Without it, MSVC++ 6.0 incorrectly regards some overloads as
+ *    specializations of a previous member function template.
+ *  - MSVC++ 6.0/7.0 seem to incorrectly treat some different memfuns
+ *    as if they have the same signature.
+ *  - If remove_const is broken due to lack of PTS, int=0 avoids the
+ *    declaration of memfuns with identical signature.
  */
 
 template<typename Type>
diff --git a/include/boost/multi_index/mem_fun.hpp b/include/boost/multi_index/mem_fun.hpp
index d083bd6..9ea90cc 100644
--- a/include/boost/multi_index/mem_fun.hpp
+++ b/include/boost/multi_index/mem_fun.hpp
@@ -30,6 +30,16 @@ namespace multi_index{
  * arbitrary combinations of these (vg. T** or auto_ptr<T*>.)
  */
 
+/* NB. Some overloads of operator() have an extra dummy parameter int=0.
+ * This disambiguator serves several purposes:
+ *  - Without it, MSVC++ 6.0 incorrectly regards some overloads as
+ *    specializations of a previous member function template.
+ *  - MSVC++ 6.0/7.0 seem to incorrectly treat some different memfuns
+ *    as if they have the same signature.
+ *  - If remove_const is broken due to lack of PTS, int=0 avoids the
+ *    declaration of memfuns with identical signature.
+ */
+
 template<class Class,typename Type,Type (Class::*PtrToMemberFunction)()const>
 struct const_mem_fun
 {
diff --git a/include/boost/multi_index/member.hpp b/include/boost/multi_index/member.hpp
index e30df53..52b274f 100644
--- a/include/boost/multi_index/member.hpp
+++ b/include/boost/multi_index/member.hpp
@@ -33,9 +33,13 @@ namespace detail{
  */
 
 /* NB. Some overloads of operator() have an extra dummy parameter int=0.
- * This is so because MSVC++ 6.0 otherwise *incorrectly* regards these
- * overloads as specializations of a previous member function template.
- * Left for all compilers as it does no harm.
+ * This disambiguator serves several purposes:
+ *  - Without it, MSVC++ 6.0 incorrectly regards some overloads as
+ *    specializations of a previous member function template.
+ *  - MSVC++ 6.0/7.0 seem to incorrectly treat some different memfuns
+ *    as if they have the same signature.
+ *  - If remove_const is broken due to lack of PTS, int=0 avoids the
+ *    declaration of memfuns with identical signature.
  */
 
 template<class Class,typename Type,Type Class::*PtrToMember>