From the XML 1.0 spec:

"An XML processor attempting to retrieve the entity's content may use the public identifier to try to generate an alternative URI reference. If the processor is unable to do so, it must use the URI reference specified in the system literal."

So if the text description of the FPI is wrong, say:

<!DOCTYPE ejb-jar PUBLIC '-//Sun Microsystems, Inc.//DTD Foo Bar Beans 2.0//EN' ...>

But the system identifier is correct:

<!DOCTYPE ... 'http://java.sun.com/dtd/ejb-jar_2_0.dtd'>

shouldn't JBoss treat the EJBs as 2.0 (assuming everything else in the deployment descriptor is ok, of course)?