The document categorizes factory overhead costs into three types: variable factory overhead includes supplies, fuel, power, small tools, spoilage expenses, royalties, and communication costs; fixed factory overhead includes overtime premium; semi-variable factory overhead consists of salaries for production supervision and repair staff, inspection, depreciation, payroll services, heat, light and power, property tax, health and accident insurance, patent amortization, maintenance and repair of machinery, rent, wages for security guards, and insurance.