hi Trey,
another option is to change the parameter Type to Number. then change the parameter so that it is an Optional parameter as well.
after this you can change your record selection filter to something like
if hasvalue({?Incentives}) then {rpt_EquipmentMaster.EquipmentType} in {?Incentives} else true
this will allow the filter to be processed at the database. if the end user does not choose a value, then all incentives will be brought back.
-jamie