Brilliant, wwh, thank you for the link!

The final thought sums it up nicely:

"But it is easy to see that there are more cases than the system of classification allows for: different degrees of integration of the part into the whole (feature or proper part of an object, coalescence of different objects, objets in a set, object in its proper environment, etc.) and different degrees of unexpectedness of the combination (pure alterity, contrariness, cultural and anthropological universals, and logical contradictions). The rhetoric of what is often confounded in the single term metonymy may turn out to be even more complex than suggested by Groupe µ’s latest contribution"

(nevermind the poor grammar)