According to the invention, a digital circuit design embodied in at least one of a structural netlist, a behavioral netlist, a hardware description language netlist, a full-custom ASIC, a semi-custom ASIC, an IP core, an integrated circuit, a hybrid of chips, one or more masks, a FPGA, and a circuit card assembly is disclosed. A runtime checker can then be used to check a received EDI document with a corresponding rule set, forward the EDI document if the EDI document matches its current rule set and return the EDI document if the EDI document does not match its current rule set. The bottom wall extends below the transfer roller.