There are 3 main categories of water types: Natural Mineral Water, Natural Spring Water and Drinking Water (Table water). Each of them has different certification requirements and standards. Both Natural Mineral Water (Medical Water) and Natural Spring water cannot be mixed with other water types and nothing must be added or taken out from the water. These two water types must stay natural as they are and must be bottled only at the water birthplace from the underground source. Exceptionally, iron may be separated. It has a natural content of minerals, but it does not have to be always constant. On the label, there must be written Natural Spring water.