The classification is based in the Classification of the Functions of Government (COFOG) developed by OECD. It classifies government expenditure data from the System of National Accounts by the purpose for which the funds are used.
General public services Executive and legislative organs, financial and fiscal affairs, external affairs; foreign economic aid; general services; basic research; R&D related to general public services; general public services n.e.c.; public debt transactions, transfers of a general character between different levels of government.
Defence Military defence; civil defence; foreign military aid, R&D related to defence; defence n.e.c.
Public order and safety Police services; fire-protection services; law courts; prisons; R&D related to public order and safety; public order and safety n.e.c.
Economic affairs: General economic, commercial and labour affairs; agriculture, forestry; fishing and hunting; fuel and energy; mining, manufacturing and construction; transport; communication; other industries, R&D related to economic affairs; economic affairs n.e.c.
(Note: in ADAPT "Agriculture, forestry, fishing and hunting", "Fuel and energy" and "Transport" are split from Economic Affairs)
Environmental protection: Waste management; water waste management; pollution abatement; protection of biodiversity and landscape; R&D related to environmental protection.
Housing and community amenities: Housing development; community development; water supply; street lighting; R&D related to housing and community amenities; housing and community amenities n.e.c.
Health: Medical products, appliances and equipment; outpatient services; hospital services; public health services; R&D related to health; health n.e.c.
Recreation, culture and religion: Recreational and sporting services; cultural services; broadcasting and publishing services; religious and other community services, R&D related to recreation, culture and religion; recreation; culture and religion n.e.c.
Education: Pre-primary, primary, secondary and tertiary education, post-secondary non-tertiary education, education non definable by level, subsidiary services to education, R&D; n.e.c.
Social protection: Sickness and disability; old age; survivors; family and children; unemployment; housing; R&D; social protection and social exclusion n.e.c.
(Note: gender should be included here)
For more information on this, visit the article Classification of Expenditure According to Purpose from UN-DESA.