This limit is only applicable if you manage Comcheks on this portal, otherwise it can be set to as 0.
This is used to bypass maximum chek limit in case your customer is in emergency. For example if customer has $200 as chek limit and it has already used $200 but needs more chek for emergency, then if this flag is set then you will be able issue one more chek equal to the amount set as Check limit. In other words it doubles maximum chek limit for one day.