These are standards that define the properties of certain in-box desiccants. DIN, standing for “Deutsches Institut für Normung”, is the German Industrial Standard, while MIL is the American equivalent. The technical pouch properties are almost identical.
All desiccants according to DIN 55473 are directly comparable with each other, as the hygroscopic and absorption speed of the desiccant pouches are defined by the standards.