In Wikipedia article (https://en.wikipedia.org/wiki/Nonparametric_statistics) about nonparametric statistics there is "Method of moments (statistics) with polynomial probability distributions" listed as non-parametric model.
How does it make sense? How method of estimation parameters can be non-parametric?
Parenthetically, is there any difference between "non-parametric" and "nonparametric"? Which is more common/correct?