diff --git a/Source/cmListCommand.h b/Source/cmListCommand.h
index ff5ebc8f4..b5193b595 100644
--- a/Source/cmListCommand.h
+++ b/Source/cmListCommand.h
@@ -80,18 +80,23 @@ public:
       "FIND will return the index of the element specified in the list or -1 "
       "if it wasn't found.\n"
       "INSERT will insert elements to the list to the specified location.\n"
-      "When specifying an index, negative value corresponds to index from the"
-      " end of the list.\n"
       "REMOVE_AT and REMOVE_ITEM will remove items from the list. The "
       "difference is that REMOVE_ITEM will remove the given items, while "
       "REMOVE_AT will remove the items at the given indices.\n"
       "REVERSE reverses the contents of the list in-place.\n"
       "SORT sorts the list in-place alphabetically.\n"
-      "NOTE: A list in cmake is a ; separated group of strings. "
+      "NOTES: A list in cmake is a ; separated group of strings. "
       "To create a list the set command can be used. For example, "
       "set(var a b c d e)  creates a list with a;b;c;d;e, and "
       "set(var \"a b c d e\") creates a string or a list with one "
-      "item in it."
+      "item in it.\n"
+      "When specifying index values, if <element index> is 0 or"
+      " greater, it is indexed from the "
+      "beginning of the list, with 0 representing the first list element. "
+      "If <element index> is -1 or lesser, it is indexed from the end of "
+      "the list, with -1 representing the last list element. Be careful "
+      "when counting with negative indices: they do not start from 0. "
+      "-0 is equivalent to 0, the first list element.\n"
       ;
     }