clarify statement

Author: ajs

doc/Language/regexes.pod6

@@ -322,7 +322,7 @@ be consumed. This means that all of these are equivalent:
     /\x2e/ and /\x002e/ and /\x00002e/
 
 But this format can be ambiguous, so the use of surrounding whitespace is
-highly recommended.
+highly recommended in non-trivial expressions.
 
 For additional provisos with respect to combining codepoints, see
 L<C<\c> and C<\C>|#regex,\c>.