AbstractFrequency, rank, and frequency‐rank distributions are distinguished and discussion then focuses on frequency‐rank distributions. The key example of frequency‐rank distributions is the so‐called “law of anomalous numbers” which, modeled as a “very mixed” Poisson process and simulated by computer, provides a means of exploring the stability of ranks in sample frequency‐rank distributions. The paper concludes with a critical discussion of the correlation of frequency‐rank distributions and offers a new measure‐the