Flywheel rotational tolerance
 

I'm in the process of reinstalling my flywheel for my 2002 Boxster 5spd. I'm referencing some pelican parts articles while doing this and I'm in need of some clarification on the flywheel inspection process if anyone has any input.

"Porsche has released a Technical Service Bulletin on checking the dual-mass flywheel (TSB 911 8/02 1360), which I have placed on the 101Projects.com website for reference. Basically, the test procedure is to twist the pressure plate surface of the flywheel about 15mm to both the left and the right and check to see if it returns to approximately its original position. If the flywheel cannot be twisted at all, or if the flywheel can be twisted beyond the 15mm without a noticeable increase in the spring force, then the flywheel is likely to be faulty."
http://www.pelicanparts.com/techarticles/Boxster_Tech/44-TRANS-Clutch/44-TRANS-Clutch.htm

My confusion is where the reference point for this 15mm is? The inner diameter or outer diameter? I can rotate my flywheel by hand and the inner diameter around outside the flywheel bolts rotates about 10 mm which ends up being 30mm on the outer diameter. I have looked for the TSB references in the article but I could not find it.