You just have to look at how the derailleurs' body move in relation to those limit screws and after that it becomes clear which one is which. Looking at the derailleur from the underside normally helps to determine that. Anyway, my guess is that for the front one, the closest to the seat tube screw would be L and the other one would be H. For the rear one, the lowest one would be H and the other one L.
Last edited by alexnagui; 08-09-20 at 08:20 AM.