diff --git a/call_traits_test.cpp b/call_traits_test.cpp
index ee4e048..4bb66b6 100644
--- a/call_traits_test.cpp
+++ b/call_traits_test.cpp
@@ -5,6 +5,7 @@
  //  in all copies. This software is provided "as is" without express or implied   
  //  warranty, and with no claim as to its suitability for any purpose.   
 
+// standalone test program for <boost/call_traits.hpp>
 
 #include <cassert>
 #include <iostream>
diff --git a/compressed_pair_test.cpp b/compressed_pair_test.cpp
index a91d4b8..ba6d81d 100644
--- a/compressed_pair_test.cpp
+++ b/compressed_pair_test.cpp
@@ -5,6 +5,8 @@
  //  in all copies. This software is provided "as is" without express or implied   
  //  warranty, and with no claim as to its suitability for any purpose.   
 
+// standalone test program for <boost/compressed_pair.hpp>
+
 #include <iostream>
 #include <typeinfo>
 #include <cassert>
diff --git a/include/boost/detail/call_traits.hpp b/include/boost/detail/call_traits.hpp
index 93dc7b1..8d02eca 100644
--- a/include/boost/detail/call_traits.hpp
+++ b/include/boost/detail/call_traits.hpp
@@ -6,6 +6,9 @@
 
 //  See http://www.boost.org for most recent version including documentation.
 
+// call_traits: defines typedefs for function usage
+// (see libs/utility/call_traits.htm)
+
 /* Release notes:
    23rd July 2000:
       Fixed array specialization. (JM)
diff --git a/include/boost/detail/compressed_pair.hpp b/include/boost/detail/compressed_pair.hpp
index a4b3390..87c2449 100644
--- a/include/boost/detail/compressed_pair.hpp
+++ b/include/boost/detail/compressed_pair.hpp
@@ -6,6 +6,8 @@
 
 //  See http://www.boost.org for most recent version including documentation.
 
+// compressed_pair: pair that "compresses" empty members
+// (see libs/utility/compressed_pair.htm)
 //
 // JM changes 25 Jan 2000:
 // Removed default arguments from compressed_pair_switch to get
diff --git a/include/boost/detail/ob_call_traits.hpp b/include/boost/detail/ob_call_traits.hpp
index 332931e..54f2739 100644
--- a/include/boost/detail/ob_call_traits.hpp
+++ b/include/boost/detail/ob_call_traits.hpp
@@ -7,6 +7,7 @@
 //  See http://www.boost.org for most recent version including documentation.
 //
 //  Crippled version for crippled compilers:
+//  see libs/utility/call_traits.htm
 //
 #ifndef BOOST_OB_CALL_TRAITS_HPP
 #define BOOST_OB_CALL_TRAITS_HPP
diff --git a/include/boost/detail/ob_compressed_pair.hpp b/include/boost/detail/ob_compressed_pair.hpp
index ce7e064..994c974 100644
--- a/include/boost/detail/ob_compressed_pair.hpp
+++ b/include/boost/detail/ob_compressed_pair.hpp
@@ -5,6 +5,7 @@
 //  warranty, and with no claim as to its suitability for any purpose.
 
 //  See http://www.boost.org for most recent version including documentation.
+//  see libs/utility/compressed_pair.hpp
 //
 /* Release notes:
    23rd July 2000:
diff --git a/type_traits.htm b/type_traits.htm
index 61f2f59..66c5370 100644
--- a/type_traits.htm
+++ b/type_traits.htm
@@ -141,7 +141,10 @@ is always defined as a compile time constant).</p>
         <td width="37%"><div align="center"><center><pre>alignment_of&lt;T&gt;::value</pre>
         </center></div></td>
         <td width="36%"><p align="center">An integral value
-        representing the minimum alignment requirements of type T.</p>
+        representing the minimum alignment requirements of type T
+        (strictly speaking defines a multiple of the type's
+        alignment requirement; for all compilers tested so far
+        however it does return the actual alignment).</p>
         </td>
         <td width="27%">&nbsp;</td>
     </tr>
@@ -454,9 +457,10 @@ will also be true.</p>
         or class. If the compiler implements the &quot;zero sized
         empty base classes&quot; optimisation, then is_empty will
         correctly guess whether T is empty. Relies upon is_class
-        to determine whether T is a class type - as a result will
-        not compile when passed an enumerated type unless there
-        is compiler support for is_enum.</td>
+        to determine whether T is a class type. Screens out enum
+        types by using is_convertible&lt;T,int&gt;, this means
+        that empty classes that overload operator int(), will not
+        be classified as empty.</td>
         <td valign="top" width="33%"><p align="center">PCD</p>
         </td>
     </tr>
diff --git a/type_traits_test.cpp b/type_traits_test.cpp
index 86a3787..719b2d1 100644
--- a/type_traits_test.cpp
+++ b/type_traits_test.cpp
@@ -4,6 +4,8 @@
 //  in all copies. This software is provided "as is" without express or implied
 //  warranty, and with no claim as to its suitability for any purpose.
 
+// standalone test program for <boost/type_traits.hpp>
+
 /* Release notes:
    31st July 2000:
       Added extra tests for is_empty, is_convertible, alignment_of.
diff --git a/type_traits_test.hpp b/type_traits_test.hpp
index 20b32d4..3e0b44e 100644
--- a/type_traits_test.hpp
+++ b/type_traits_test.hpp
@@ -5,6 +5,7 @@
  //  in all copies. This software is provided "as is" without express or implied   
  //  warranty, and with no claim as to its suitability for any purpose.   
 
+// common test code for type_traits_test.cpp/call_traits_test.cpp/compressed_pair_test.cpp
 
 
 #ifndef BOOST_TYPE_TRAITS_TEST_HPP