The first documented regulations of the NMC were issued for the 5th NMC in 1991. (See image.) They were applied unaltered in 1992 and apparently with at most minor changes in the following years. According to these regulations students in a 'gymnasium' (10th–12th school year in the educational systems of the Nordic countries, in the regulations referred to as the 'upper school') are eligible to participate without any age limit. The curriculum comprises "any branch of mathematics suitable for upper school students", and it is stressed that it is thus broader than that of the IMO. In particular, "problems from calculus and elementary probability theory" may occur. The subjects of most of the problems that have been posed at the NMC actually lie within the traditional IMO curriculum. However, problem 4 in 2002 must be deemed outside this curriculum since its formulation involves the concept of probability. No aim of the NMC is specified in the 1991 regulations.