The formal structure of the IPhO was established in 1968 at a dedicated meeting in Czechoslovakia, soon after the second IPhO. There the statutes and the syllabus were officially accepted by the International Board, which consists of the delegation heads from all participating countries. The team size was finally set to five students in 1971, and in 1976 the number of experimental problems was set to one or two, while there are three theoretical problems in each competition. In 1984, the IPhO established a permanent secretariat and a president's office. This position was held by Dr. Waldemar Gorzkowski until the 2007 Olympiad, then Prof. Maija Ahtee (2007–2008), Prof. Hans Jordens (2008–2018) and Prof. Rajdeep Singh Rawat (2018 onwards). Since 1984 the IPhO has collaborated with UNESCO for moral support and publicity. An advisory committee, consisting of 14 experienced people, was introduced in 1996.