I think you have 17s which means that you have the PS2 if you are running a summer Pilot Sport.
http://www.tirerack.com/tires/tires.jsp?tireMake=Michelin&tireModel=Pilot+Sport+PS2&frontTire=05YR7SPORTPS2N3&rearTire=54YR7SPORTPS2N3&vehicleSearch=true&fromCompare1=yes&autoMake=Porsche&autoYear=2000&autoModel=Boxster S&autoModClar=
It is an asymmetric tread so you can swap the tires from side to side.
disclaimer: I have read that once a tire rolls a certain way it is "fixed" in that direction and not to move it to the other side, but then I also read that is for old technology tires. My Toyota FJ Cruiser has asymmetric tires but my old dealer in NC would only rotate them front to back for that reason. But he was "old school"
When I talked with the folks at Tire rack they said that asymmetric tread would always have the word "asymmetric", and directional tread would always say "directional" in the description. If a tire says neither of these keywords then it is neither, although I understand that is rare these days.
Edit: When I had my Sumitomo HTR Z III, an asymmetric tread, I never rotated them side to side, but that was because I thought I could not. I probably would have if I had known I could.