That is correct. You can flip-flop (rotate from side to side) for tires that have directional and symmetrical tread patterns...like the Yoko AO48. If you have staggered sizes with directional and symmetrical tread like the Exige (assumes AO48s), this is the only rotation pattern you can use.
You cannot do it with directional tires that have asymmetrical patterns, because each sidewall is specific to (and marked accordingly for) an inside or outside location per the manufacturers' mounting specs (for wet use / water evacuation, dry cornering, etc.).
If your car has negative camber, the inside tread will wear slightly faster. Rotating from side to side will help even out the wear.
It will require having the tires remounted and rebalanced. I usually mark the outside sidewall with an X in white chalk to make it easier to explain to the tire shop that I want the Xs on the inside once the tires are remounted. :huh: You'd be surprised at how some people don't get it at first.
I just completed this rotation on the street tires (Toyo T1Rs) for my Exige. At 15,000 miles of use, the inside of the fronts (-1.0 degree camber) had worn about 10% more than the outside tread, and the inside of the rears (-2.25 degrees of camber) about 20% more than the outside tread. With the rotation, I hope to maybe get to 25,000+ miles on the T1Rs. My track tires (AO48s) will likely get the same rotation so I can squeeze another track day or two out of them.