felix commons

[Hampel, Michael]

Hello,
 
I have a question regarding the poms in Felix Commons.
Some of these poms prohibit the import of javax packages by adding
!javax.* to the <Import-Package> element,
others are not doing it like avalon or log4j.
Should I import  JRE classes or not - is this because they are loaded by
the system bundle?
 
Thanx in advance for any help,
 
Michael