Please add a Rational description to the manual/online documentation
It would be extremely helpful to have a Rational as part of the online documentation. The online document is GREAT, but there is a lack of understanding why items could be used, can be used, should be used, or where not to use. For example take any Diagram (go to documentation). It is Ok to tell us "How to create an include or extend", but it would be very helpful, WHY this should be done, i.e., having a rational behind this. Besides the excellent images in documentation, one user can only guess what he needs and why he could do it that way. A precise definition should be added. Unfortunately no images can be added to this uservoice platform, so I can only try to explain it. I hope this gets some attention for further improvement of the already good documentation. Kind Regards