From the website below: . . . USD 0.003/Share Additional fee for API equity directed orders. USD 0.12/Cancelled Order For API equity directed order cancellations. USD .24 credit against cancellation charges given for each API equity directed order execution. . . . I coudn't find any details on what API means, other than other companies using the API to create order platforms. Is this an extra charge if another app besides TWS is used to enter the order?