Weed control products are classified into three categories; Domestic (for home use), Commercial (for the lawn industry), and Restricted (for special use, typically under a special permit). A pesticide applicators license is required to apply commercial or restricted pesticides. Commercial and restricted weed control products contain the highest levels of active ingredient. That is to say, when used according to directions, they will work most effectively. Domestic weed control products are typically formulated at concentrations of 50% or less than 50% compared to commercial weed control products. Thus, domestic weed control products tend to be less effective, requiring more frequent applications.