You can label any chargeback as "forgiven" from a fraud perspective.
If a chargeback is forgiven, it will no longer prevent a customer from transacting. Forgiving a chargeback is therefore often a preferable choice to reviewing the customer as Genuine.
If a customer is only prevented due to the chargeback, they will be able to transact again as soon as their chargeback is forgiven. However, if they are additionally being prevented by any other sources (such as rules, a manual review, an additional unforgiven chargeback or a high fraud score for example), they will continue to be prevented from transacting in spite of the forgiven chargeback.
You can chose to forgive or unforgive an individual chargeback from the options menu on that chargeback.
Forgiven chargebacks have a grey chargeback icon and show the time of the decision.
Unforgiving a chargeback simply returns the chargeback to its original state, where it will continue to prevent the customer and any linked customers in their network from transacting.