--- a/List.st	Fri Nov 08 09:36:33 2019 +0100
+++ b/List.st	Sat Nov 09 19:42:20 2019 +0100
@@ -168,7 +168,9 @@
 !
 
 addAll:aCollection beforeIndex:index
-    "insert all elements of the argument
+    "insert all elements of the argument, anObject to become located at index.
+     The collection may be unordered, but then the order of the sliced-in elements
+     is undefined.
      Return the receiver."
 
     self possiblySynchronized:[