Information Hiding/Encapsulation (IH/E): PSU is about constructing a module such that its inner workings (and its usage also) can be understood without knowledge about other modules. IH/E on the other hand is about constructing a module in a way that hides the inner workings so it can be used without knowing them.
Low Coupling (LC): One kind of couplings are logical couplings. These are especially hard to detect but should be avoided. PSU describes one aspect of these logical couplings, whereas LC relates this kind of coupling to others.
Model Principle (MP): The model contains the only information that should be necessary to understand the module.