Can jar files be added to the root of an EAR file?

Issue

• From the document at https://docs.jboss.org/author/display/AS71/Class+Loading+in+AS7 it appears the EAR root folder should contain only EJB and WAR jar files and other jar files should be placed in the EAR/lib folder.
  Could you clarify whether or not this is a mandatory packaging policy ?
• Is it OK to package regular (non-ejb, non-war) jar files in the EAR root folder ?
• We've experienced stranges java.lang.LinkageError issues in some enterprise application appearing just after the application server restart.