Design Guidelines / Goals / Principles
Describe any specific goals you have for your design, or constraints you have placed on your design.
Also give your motivation.
E.g.
"The presentation layer will only communicate
with the application layer through the
facilities provided in the facade controller.
The reason for this is the likelihood that the
underlying application layer implementation
will change as (Insert something here) are
added to the system. (Lowers the coupling,
and thus facilitates easier modification)."