In java EE, which jars should I put in the library dir?

Question

I have a Java EE project. The project is built using maven into an .ear archive. There is a library jar containing a JPA 2 persistence unit, which is located in the library

Answer 1

This article has a great table explaining things:

Table 2 A standard archive may load classes either packaged inside it or from any other archives it is dependent on.

Module      Code Sources
EAR 
            All JARs in the /lib directory of the EAR
            Manifest Class-Path of any JARs in 1
EJB-JAR 
            EJB-JAR file itself
            JARs referenced by manifest Class-Path of EJB-JAR
            JARs referenced by manifest Class-Path of above JARs (in 2)
WAR 
            WEB-INF/classes
            JARs in WEB-INF/lib
            JARs referenced by manifest Class-Path of WAR
            JARs referenced by manifest Class-Path of JARs in 2 and 3