Abstract: A game primarily though not exclusively intended for mass-communication media such as radio, television and newspapers and periodicals, involves the answers to a set of questions being assembled, for example, as numbers, according to a predetermined explicit or problematic algorithm into an instruction such for example as a telephone number by means of which the first solver can identify himself and claim a prize.

Abstract: A method for use in the detection of fake mass-produced articles that may be apparently identical to genuine articles involves marking genuine articles with a unique or restricted code mark generated by a secret algorithm, the gamut of such marks being underutilized so that attempts to generate seemingly genuine marks without knowledge of the algorithm will stand only a small chance of success. The marks can be scrutinized for genuineness--whether or not they conform to the algorithm--by a programmable hand held calculator or by a computer. Since one way to produce a seemingly genuine mark would be to copy genuine marks, the calculator or computer is also programmed to detect whether any particular mark has been read before.