Classifications and definitions

• IFOAM.bio: Definition of Organic Agriculture
• IFOAM.bio: Principles of Organic Agriculture
• IFOAM.org: IFOAM Family of Standards
• FAO.org: FAO Glossary on Organic Agriculture

• FAO.org: Glossary for all agricultural data
• FAO.org: Definition of land use types including land use in organic agriculture: Go to "Inputs" and then "Land" for land use definition

• FAO.org:  FAOSTAT commodity list
• FAO.org: Items/crops by group
• FAO.org: Definition of crops
• FAO.org: Codes and definitions for all domains: Go to production for crop and livestock names/codes/definitions
• FAO.org: Commodity classifications

International

• UNSTATS.UN.org: Central Product Classification (CPC) Ver.2.1
• UNSTATS.UN.org: Standard International Trade Classification, Rev.3
• UNSTATS.UN.org: List of international family of economic and social classifications

European Union

• EC.Europa.eu: Eurostat's Metadata Server RAMON, with links to key European classifications
• EC.Europa.eu: PRODCOM List 2013, Metadata
  PRODCOM is the title of the EU production statistics for Mining, Quarrying and Manufacturing, i.e. Sections B and C of the Statistical Classification of Economic Activities in the European Community (NACE Rev. 2). The title comes from the French "PRODuction COMmunautaire" (Community production).
• EC.Europa.eu: Statistical Classification of Products by Activity in the European Economic Community, 2008 version (CPA 2008)
  The CPA is the European version of the CPC, and the purposes it serves are in line with those of the CPC. Whilst the CPC is merely a recommended classification, however, the CPA is legally binding in the European Community. In addition, the specific survey classifications were and are linked to the CPA unless the CPA is itself used as a survey classification.
• EC.Europa.eu: Combined Nomenclature, 2014
  The Combined Nomenclature is the goods classification used within the EU for the purposes of foreign trade statistics. It is also used by Directorate General "Taxation and Customs Union" of the European Commission for customs duty purposes. The classification is maintained by Eurostat for the statistical aspects and by Taxation and Customs Union DG for the tariff aspects.
  The classification is based on the Harmonized System (HS) which it sub-divides where necessary for purposes of external trade, agricultural regulation and customs duties. The CN was introduced in 1988 together with the HS. Subheadings in the CN are identified by means of an eight-digit numerical code. The very considerable number of subdivisions within the CN were introduced with the EU's specific customs and foreign trade statistics requirements in mind. The CN is revised annually and, as a Council Regulation, is binding on the Member States.

• EUR-Lex.Europa.eu: COMMISSION REGULATION (EU) No 575/2011 of 16 June 2011 on the Catalogue of feed materials (Text with EEA relevance). Official Journal of the European Union, 17.6.2011
• EUR-Lex.Europa.eu: Commission Regulation (EU) No 575/2011 of 16 June 2011 on the Catalogue of feed materials Text with EEA relevance. OJ L 159, 17.6.2011, p. 25–65. With access to all language versions BG, ES, CS, DA, DE, ET, EL, EN, FR, IT, LV, LT, HU, MT, NL, PL, PT, RO, SK, SL, FI, SV

UNSTAT.UN.org: Classifications Registry
FAOSTAT.FAO.org: Other international classifications