Joe, the gold fingers (pads) porosity requirement is to ensure the connector reliability for card edge connector applications. The pad has a critical zone where connector spring contacts the pad. If it is not pore free, corrosion is likely to develop that may cause intermittent or opens. Second issue arises when card is inserted into edge connector. Again if the pad edges have porosity and hence corrosion product, it will get dragged into contact area during insertion causing connector reliability. I have seen that occur many times in product assurance testing for reliability. Third, the wear of gold plating is also affected by porosity again leading to contact reliability issues. There are many excellent papers on the subject.The two of these are given below for reference. If you need further assistance or wish to discuss, please call. Pratap Singh RAMP Labs (512) 255-7820 REFERENCES 1."Corrosion Through Porous Gold Plate" by S.J. Krumbein, June 1969, pp89-98, IEEE transactions on Parts, Materials and Packaging. 2."Corrosion of Porous Gold Plating in Field and Laboratory Environments" by WH Abbot, pp 72-75, November 1987, Plating and Surface Finishing.