On the deflationary nominalist picture, ontological commitment is not signaled in any special way in natural (or even formal) language. We just don't read off the ontological commitment of scientific doctrines (even if they were suitably regimented). After all, without Quine's criterion of ontological commitment, neither quantification over a given object (in a first-order language) nor formulation of true claims about such an object entails the existence of the latter.