--subdivision Control under individual weeds and groups of weeds, e.g. Prickly pears--Control; Aquatic weeds--Control; and subdivision Weed control under individual crops and groups of crops, e.g. Corn--Weed control
--subdivision Chronology under names of individual persons, sacred works, literatures, wars, individual art forms, headings for national or ethnic art, and topical headings that are inherently historical; and subdivision History--Chronology under names of countries, cities, etc., and individual corporate bodies, and under ethnic groups and topical headings that are not inherently historical