The options of DG elements linked with the mesh shape

Hi, all

In the DG methods to solve the Stokes equation, NGSolve provides P_k elements if we use a triangulation, or Q_k elements if a quadrilateral mesh used.

Under the DG methods in NGSolve, how can we still use P_k elements (discontinuous) in each quadrilateral element over a quadrilateral mesh?

Di Yang