Review of working draft 04 rev. 2

Hi all,

attached working draft 04 of the PbD-se specification with my review comments and edits. I only had time to have a look at chapters 1, 2 and 4. 

As mentioned on the last call I think it is better to move chapter 5 to an appendix or a separate document (for example a Committee Note) as it contains only non normative material. 

Regards
Sander