The Bureau of International Expositions (or Bureau International des Expositions) is the organization responsible for sanctioning World's fairs. It is based in Paris, France and was established as an international convention in 1928. However, many fairs take place unsanctioned, e.g. the 1964/1965 New York World's Fair.

Potential host nations can apply to the BIE to hold a BIE-sanctioned Expo to celebrate some special event, to represent some concept, or for some other them. BIE currently uses three classes: universal, international, and specialized. Historically other classification systems have been used.

From 1933 (when the treaty came in to effect) until 1976, there were 2 types of expos:

• Universal (or General) Exposition, including:
  • General Exposition 1st category - at which each country had to build its own pavilion,
  • General Exposition 2nd category - at which the pavilions were built by the expo.
• Specialized (or international) exposition, where the expo would build the buildings.

Unlike the universal exposition, there was no time limit between specialized expositions. However, at some of the specialized expos, some countries did indeed build their own pavilions (Liege 1939 was such an event). And another little-known fact is that Seattle Century 21 Exposition 1962 was actually a "universal" exposition (General Exposition 2nd category) in the same category as Paris 1937 and 1939 New York World's Fair (at both of which countries should not have been allowed to build their own pavilions).

The second phase of categories came under the 1972 protocol - which came in to force after Expo '75. Under that system there were just 2 types, Universal (the categories being combined) and International (or specialized) - where at a universal expo each country could build its own pavilion, but buildings could be provided for poorer countries. At an international expo, the expo built the pavilions. Also, the theme at a universal expo was larger or more open. Only Expo '92 in Seville and Expo 2000 in Hanover have been held in this category.

The new categories, under the 1988 protocol, came in recent years. There are 2 types - "registered" and "recognized". The registered expos are to be every 5 years starting in 2010 (Expo 2005 was registered under the 1972 protocol, but decided to follow the new system anyway). It is up to each expo if they will let each country build its own pavilion or not, but the BIE has let it be known that they wish that only the expos in the "10 years" (2010, 2020 etc...) have countries building their own pavilions and the ones in the "5s" that the expo should build the buildings. In between these registered expos, there will be one recognized expo - which can be held for only 3 months and be no bigger than 25 hectares. Expo 2004, which was not held, would have been the first of this type. Both Genoa Expo '92 and Taejon Expo '93 were held as "test runs" for this type.

See also

• List of world's fairs

External link

• Bureau of International Expositions