Programs outside the formal system of regular schools, colleges, universities and technical/trade schools that provide opportunities for adults to develop basic learning or communication skills, complete their high school education, expand their knowledge in a particular field or discipline or explore and develop skills in a new area of interest. Instruction may be provided by a school system, college, or other agency or institution through activities and media such as formal classes, correspondence study, radio, television, lectures, concerts, demonstrations, and counselling. For continuing education and training programs in specific fields, use coding in the major field area that best describes the field in which training is offered.