I don't know about exceptions, but you're looking at the emulsion side if you hold the film so that the long side of the sheet is on top and bottom, and the short side of the film is on right and left. Under that circumstance the notches will be on the right hand side, in the lower corner, (on the short vertical side).
If you hold the film 90 degrees clock-wise rotated from that, with the long dimension on the sides, and the short dimensions on top and bottom, that same notch would be in the lower left hand corner, (still on the short side of course, but now horizontal).
It depends on how you're holding the film.