CPA classification (Classification of Products by Activity) is European statistical classification of products, accepted in 1993. CPA includes all economical outputs, goods as well as services. CPA assures  unified European frame for statistical data comparison regarding goods and services.

NACE classification (Nomenclature Générale des Activités Economiques dans les Communautés Européennes - Classification of Economic Activities in the European Community) represent the statistical classification of economic activities within the  European Union which serves as a basis for compiling statistics on the production, factors of production (labor, raw materials, energy, etc.).

CPC classification (Central Product Classification) is the devised by the Statistical Department of the United Nations Secretariat.

CPV classification (Common Procurement Vocabulary) is a coding system used by the European Union in public procurement transactions used to group together the products of similar producers.

CPC classification

CPV classification

NACE classification

CPA classification