Magnetically or optically detectable elements are arranged on a substrate
so as to encode information to be stored. An information carrier comprises a plurality
of individual detectable elements supported by, or incorporated in, a substrate
wherein the spacing between the elements serves to encode the information and is
such that it can be represented as A+MG, wherein A is a first fixed value, m is
an integer (which may be zero) and G is a second fixed value, characterized in
that the values of the integer m, are selected to be integers derived by a predetermined
mathematical sequence or a random sequence generator.
