The Related Records feature enables the user to verify whether a customer credit memo has been created. Duplication will be avoided because of their ability to quickly identify the existence of a credit memo for a sales invoice. In addition, if user has access to view the Customer Credit Memo information, he can review the details by simply navigating to that transaction.
To determine whether a Customer Credit Memo has been created, navigate to the Customer Credit Memo Table and look for an existing hyperlink. If there is none, it means that no sales invoice has been created.
As for the Customer Credit Memo, users can still create new credit memo as the system will not conduct any duplication validation.