To name pathotypes of plant pathogens, a variety of systems of designation has evolved, which was evaluated to find out the systems best suited. Virulence and avirulence/virulence formulae of pathotypes are by far advantageous over the use of consecutive numbers or letters given in chronological order of pathotype discovery. As soon as pathotype information surpasses a certain level of complexity, mathematical codes are most advantageous and, in particular, octal notation and coded triplets (tripletcode). To ease communication and comparisons of results, a more universal adoption of the most appropriate codes is recommended.