diff --git a/include/boost/endian/conversion.hpp b/include/boost/endian/conversion.hpp
index 1d89596..1e502d5 100644
--- a/include/boost/endian/conversion.hpp
+++ b/include/boost/endian/conversion.hpp
@@ -52,7 +52,11 @@ namespace endian
 //                                                                                      //
 //--------------------------------------------------------------------------------------//
   
-  //  customization for exact-length arithmetic types. See doc/conversion.html/#FAQ
+  //  customization for exact-length arithmetic types. See doc/conversion.html/#FAQ.
+  //  Note: The omission of an overloads for the arithmetic type (typically long, or
+  //  long long) not assigned to one of the exact length typedefs is a deliberate
+  //  design decision. Such overloads would be non-portable and thus error prone.
+     
   inline int8_t   endian_reverse(int8_t x) BOOST_NOEXCEPT;
   inline int16_t  endian_reverse(int16_t x) BOOST_NOEXCEPT;
   inline int32_t  endian_reverse(int32_t x) BOOST_NOEXCEPT;