diff --git a/doc/src/sgml/ddl.sgml b/doc/src/sgml/ddl.sgml
index 98fcc7c44a1..06f2c320a7b 100644
--- a/doc/src/sgml/ddl.sgml
+++ b/doc/src/sgml/ddl.sgml
@@ -1879,7 +1879,11 @@ REVOKE ALL ON accounts FROM PUBLIC;
      <listitem>
       <para>
        Allows creation of a foreign key constraint referencing a
-       table, or specific column(s) of a table.
+       table, or specific column(s) of a table. Great care should be taken when
+       granting this privilege, since a user who creates a foreign key can arrange
+       for enforcement of that foreign key to call an arbitrary function, such as
+       a cast function, and such functions will be called with the privileges of
+       the table owner.
       </para>
      </listitem>
     </varlistentry>
@@ -1888,7 +1892,9 @@ REVOKE ALL ON accounts FROM PUBLIC;
      <term><literal>TRIGGER</literal></term>
      <listitem>
       <para>
-       Allows creation of a trigger on a table, view, etc.
+       Allows creation of a trigger on a table, view, etc. Great care should be
+       taken when granting this privilege, since any triggers added to a table
+       or view will be executed with the privileges of users who modify it.
       </para>
      </listitem>
     </varlistentry>