we call them parameters these days and we indent examples with 4 spaces

doc/Language/typesystem.pod6

@@ -542,7 +542,7 @@ comma can be provided. In this case conflicts will be reported at compile time.
 
 For runtime mixins see L<but|/language/operators#infix_but> and L<does|/language/operators#infix_does>.
 
-=head3 Role Arguments
+=head3 Role Parameters
 
 Roles can be provided with parameters in-between C<[]> behind a roles name.
 X<|Type Capture (role)>L<Type captures|/type/Signature#Type_Captures> are supported.
@@ -554,14 +554,14 @@ X<|Type Capture (role)>L<Type captures|/type/Signature#Type_Captures> are suppor
     dd $c;
     # OUTPUT«C $c = C.new(a => "default")␤»
 
-Arguments can have type constraints, C<where> clauses are not supported but can
+Parameters can have type constraints, C<where> clauses are not supported but can
 be achieved via C<subset>s.
 
-   class A {};
-   class B {};
-   subset A-or-B where * ~~ A|B;
-   role R[A-or-B ::T] {};
-   R[A.new].new;
+    class A {};
+    class B {};
+    subset A-or-B where * ~~ A|B;
+    role R[A-or-B ::T] {};
+    R[A.new].new;
 
 Default parameters can be provided.