These attributes are private to a Routine. They can be edited and formatted just as for Portal and other attributes. Routine attributes get set to the initial (edit) value whenever the routine is invoked.
Routine Attributes cannot have stat display views created for them, however you can access their last-set values if you pause the model and open the Routine change object, the attribute values will be visible from the "Routine Attributes" menu
You can also use Routine attributes in a dialog, if you want to access or view them while a model is running. It is often useful to transfer a portal attribute or table cell value over to a routine attribute when you wish to display these is a dialog, since the reference is local. The setting of the screen name (required in a dialog portal or table attribute reference) is then no longer an issue, and this makes control-pasting possible without having to do manual maintenance of this screen identifier.