index S and R meta ops

doc/Language/operators.pod6

@@ -201,6 +201,7 @@ There are shortcuts for C<!==> and C<!eq>, namely C<!=> and C<ne>.
     say so $release !before $today; # True
 
 =head1 Reversed Operators
+X<|R,reverse meta operator>
 
 Any infix operator may be called with its two arguments reversed by prefixing
 with C<R>. Associativity of operands is reversed as well.
@@ -356,6 +357,7 @@ If infix operator is not given, C<,> (comma operator) will be used by default:
     my @l = 1 Z 2; # [(1 2)]
 
 =head1 Sequential Operators
+X<|S,sequential meta operator>
 
 The sequential metaoperator, C<S>, will suppress any concurrency, or reordering
 done by the optimizer. Most simple infix operators are supported.