The number of days from the transaction request day that the unconfirmed authorization can remain unreversed even if settlement process occurs. When settlement happens and the transaction authorization period is not being reached (transaction is not expired), transaction is transfered into the next retail cycle.
Number of days during which an authorization can remain unsettled. When the value is greater than 0, any un-captured (unconfirmed) transactions will not be reversed until the expiration period is reached.
Note: the value of the expiration period cannot exceed the lifetime of an authorization allowed by the processor that was used to get it.