diff --git a/doc/src/sgml/notation.sgml b/doc/src/sgml/notation.sgml
index bd1e8f629a..77499e8507 100644
--- a/doc/src/sgml/notation.sgml
+++ b/doc/src/sgml/notation.sgml
@@ -11,7 +11,7 @@
   (<literal>{</literal> and <literal>}</literal>) and vertical lines
   (<literal>|</literal>) indicate that you must choose one
   alternative.  Dots (<literal>...</literal>) mean that the preceding element
-  can be repeated.
+  can be repeated.  Parentheses should be interpreted literally.
  </para>
 
  <para>