STYLE: fix bug 5682

Source/cmMacroCommand.h

@@ -97,12 +97,19 @@ public:
       "macro are first modified by replacing formal parameters (${arg1}) "
       "with the arguments passed, and then invoked as normal commands. In "
       "addition to referencing the formal parameters you can reference "
-      "the variable ARGC which will be set to the number of arguments "
-      "passed into the function as well as ARGV0 ARGV1 ARGV2 ... which "
+      "the values ${ARGC} which will be set to the number of arguments "
+      "passed into the function as well as ${ARGV0} ${ARGV1} ${ARGV2} "
+      "... which "
       "will have the actual values of the arguments passed in. This "
       "facilitates creating macros with optional arguments. Additionally "
-      "ARGV holds the list of all arguments given to the macro and ARGN "
-      "holds the list of argument pass the last expected argument.";
+      "${ARGV} holds the list of all arguments given to the macro and "
+      "${ARGN} "
+      "holds the list of argument pass the last expected argument. "
+      "Note that the parameters to a macro and values such as ARGN "
+      "are not variables in the usual CMake sense. They are string "
+      "replacements much like the c preprocessor would do with a "
+      "macro. If you want true CMake variables you should look at "
+      "the function command.";
     }
 
   cmTypeMacro(cmMacroCommand, cmCommand);