DATADOC-59 - Document @Query annotation for repositories

src/docbkx/reference/mongo-repositories.xml

@@ -294,6 +294,9 @@ public class PersonRepositoryTests {
   List<Person> findByThePersonsFirstname(String firstname);
 
 }</programlisting>
+
+      <para>This will return only the firstname, lastname and Id properties of
+      the Person objects, for example age will be null.</para>
     </section>
 
     <section>