Controlled Wood is material that can be mixed with certified material during manufacturing FSC mix products. This has enabled manufacturers to manage low and fluctuating supplies of FSC certified forest products, while creating demand for FSC certified wood. Only materials from FSC-acceptable sources can be used as controlled. There are 5 categories of unacceptable material that cannot be mixed with FSC certified materials: illegally harvested wood, wood harvested in violation of traditional and civil rights, wood harvested in forests in which High Conservation Values are threatened by management activities (HCVs are areas particularly worth of protection), wood harvested in forests being converted to plantations or non-forest use and wood from forests in which genetically modified trees are planted. The controlled materials can be verified either by the manufacturer according to the 'company' standard for Controlled Wood (FSC-STD-40-005) or through Controlled Wood Forest Management certification, according to the standard FSC-STD-30-010. Controlled Wood standards are related to both the Forest Management and Chain of Custody certification.