The enterprise bean must not attempt to use the subclass and object substitution features of the Java Serialization Protocol.
But on p. 73,
While the container is not required to use the Serialization protocol for Java Programming language to store the state of a passivated session instance.....
The first quote says the bean cannot use object substitution of Java Serialization Protocol.
The second quote says the container is not required to use the Java Serialization Protocol for @PrePassivate and @PostActivate.
Are these two conflicting each other ?
(source: EPractice Lab asks about EJB restrictions.)