How Credit Memo and Returns work in Advanced Revenue Management?

Hi Gurus!

I need to better understand how returns work in terms of ARM/Advanced Revenue Management.

I read up on it in the User Guide, and essentially it looks like returns can be based on Return Authorizations and Credit Memos and in both cases a negative revenue element revenue arrangement is created and merged with the original revenue arrangement.

Question please: Do you by chance happen to have brief but comprehensive use case with screenshots that would walk someone through the process end to end?

It would be ideal see one use case for a "delivery" type of item (when rev plans are created upon delivery at a point in time) and an "over time" type of item (when rev plans are created upon revenue arrangement creation and revenue is recognized evenly over time).