I'm trying to understand how to order two modules (registration and comments, but that's not relevant) that share the same position.
Suppose that I have comments on top and registration after the comments and I want to reverse that order.
When I edit the module there is a "Ordering" field, but I can't understand how to use it to change the order.

Ok, I just found it myself: I edited the module that was displayed 1st (at the top) and I changed the "Ordering" combo box associated to it, putting it into second position.