  :Unless it can be ruled out as original research (and it seems it cannot), the concept is certainly worthy of inclusion. Merging with Federation is in any case a bad idea, as the concepts are clearly distinct (or in same cases maybe a little less clearly, see Russia below).     == Examples == === Serbia === Shouldn't the relation between Serbia and Kosovo/Vojvodina be listed? If I have understood the definition correctly, it seems to be a clear-cut case.     === The Netherlands === If we necessarily must mention this, I think the article should be clearer that it can only be a de facto federacy relation. Constitutionally, the three parts of the Kingdom of the Netherlands are equal (correct me if I'm wrong), so it can have no federacies. Also, constitutionally, Aruba and the Netherlands Antilles are not part of the Netherlands, so that can't have any federacies either.     === United States === In which way does Puerto Rico have significantly larger autonomy than the other top-level administrative divisions of the US (i.e., the states, the DC, and the other insular areas)?     === Russia === I've added Russia to the Asymmetric federation article. I don't think differences between federal subjects qualify for federacy, but I can be wrong   