ABSTRACT
In Optimality Theory, a set of grammatical constraints defines a set of implicational universals that hold among <input, output> pairs. We call this structure a T-order. T-orders have a useful application in the study of variation: they impose universal limits on variation that hold under several theories of variation, including Multiple Grammars, Partially Ordered Grammars, and Stochastic Optimality Theory, and that emerge quantitatively in empirical variation data. A detailed illustration from variable stress assignment in Finnish will be provided.