A tab for attaching to sheet material comprises a substrate including a front side, a back side opposite the front side, an upper portion, a middle portion, and a lower portion. The enhanced stability bipolar plate includes a bipolar plate substrate and a corrosion-resistant coating thermally sprayed on the bipolar plate substrate. For example, when the archive condition is the archive period, control is executed to delete data that has expired. The coupler and the male coupler are connected one with the other by brazing. Aperture density obtained by dividing by is higher than aperture density obtained by dividing by, while embossment density obtained by dividing by is higher than embossment density obtained by dividing by.