Have done my first couple of trips at Orly.
Hard to believe how confusing the signage is within the airport.
Luckily I had carefully read all the details provided by my fellow FTers.
But I could see foreign pax completely flabbergasted.

At some points there were signs for "gates 11-14" and just below "Gates B, C, D" (I don't remember the exact numbers letters). No indication for Orly 2, 3 or 4.
Why not call the numbered gates A11-A14? Why no indications of Orly 2 rather than gates C?
I helped some Asian pax who had a transfer and could not understand how to use the signs.