Hierarchy

 The hierarchy concept is pretty simple, things that have more dependencys are at the top or higher level while those width less dependecy are at the lower level.

A login pseudo object does not need to be in the top level, since is only used at the login interface.

• char login;
• char login_name;
• char login_user;
• char login_password;
• char login_db;

In here we have a raw example that shows a formant on a pseudo object that is done to handle or manage a login menu. But lets assume that afther we implement 1 login we whant to add another in this case it have more dependencys and it raises in hierarchy, can go up to global or a inter mid step of local to global. Like a interface or template for the login. 

This file is not local nor global. Not all things will use login and since more then 1 are using the login, is place is not local nor global. But this depends on how you evolve and implemente, this is more a theory.

At the moment their is no rule for this because this depend on the abstraction done, which depends also on performance needed more abstraction lead to more slow and memory consumption while more raw create a more dificult software to maintain but faster.