outlaw macro-ish traits on multi

Author: TimToady

S06-routines.pod

@@ -16,8 +16,8 @@ Synopsis 6: Subroutines
 
     Created: 21 Mar 2003
 
-    Last Modified: 8 Nov 2011
-    Version: 153
+    Last Modified: 23 Jan 2012
+    Version: 154
 
 This document summarizes Apocalypse 6, which covers subroutines and the
 new type system.
@@ -2185,6 +2185,11 @@ Likewise 0-ary functions parse as listops.  Use C<< term:<foo> >>
 (or a constant or enum declaration) to declare a term that expects
 no arguments.
 
+Because these traits have an immediate declarative effect, it is
+illegal to apply them to a C<multi>, or to any post-declared function.
+More generally, any such language-bending declaration must follow
+the same lexical scoping rules that a macro does.
+
 =item C<is assoc>
 
 Specifies the associativity of an operator explicitly.  Valid values are:
@@ -2205,6 +2210,9 @@ and other operators defined at that level are required to be the same.
 Specifying an C<assoc> without an explicit C<equiv> substitutes a default
 C<equiv> consistent with the associativity, as shown in the final column above.
 
+Because this trait has an immediate declarative effect, it is illegal
+to apply it to a C<multi>, or to any post-declared function.
+
 =item C<PRE>/C<POST>
 
 These phasers declare statements or blocks that are to be unconditionally