structural:summarization, structural:scholar_edition
World Expos

World Expos (formally known as International Registered Exhibitions) encompass universal themes that affect the full gamut of human experience, and international and corporate participants are required to adhere to the theme in their representations. Registered expositions are held every 5 years because they are more expensive as they require total design of pavilion buildings from the ground up. As a result, nations compete for the most outstanding or memorable structure—for example Japan, France, Morocco, and Spain at Expo '92. Sometimes prefabricated structures are used to minimize costs for developing countries, or for countries from a geographical block to share space (i.e. Plaza of the Americas at Seville '92).

In the 21st century the BIE has moved to sanction World Expos every five years; following the numerous expos of the 1980s and 1990s, some see this as a means to cut down potential expenditure by participating nations. The move was also seen by some as an attempt to avoid conflicting with the Summer Olympics. World Expos are restricted to every five years, with Specialized Expos in the in-between years.