Introduction
The Olympiad is organized by the Ministry of Education or another appropriate institution of one of the nine Central European countries. Croatia, Czech Republic, Germany, Hungary, Poland, Romania, Slovak Republic, Slovenia and Ukraine, are invited as regular participants.
Moreover, the host country may invite guest countries and a second team from the host country, sharing the same team leader. The International Committee (IC) of the CEOI consists of the nine team leaders, and a representative of the host country, who chairs the meetings of the IC. A host which is willing to organize a CEOI in a given year in its country, has to announce its intent at least one year before that CEOI (during the previous CEOI competition days).
Selection of the next host is made by the IC by a majority vote. Revision of the Regulations of the CEOI is adopted by the IC by a 2/3 majority vote. Enlarging or decreasing the set of CEOI countries can only be adopted by consensus.