Steve's patent is a "utilitarian patent" (no pun intended). To be patented, he needed to come up with an improvement that is unique to his skirted garment and it had to serve a utilitarian purpose. His "box pleating system" helps to:

"Therefore, in light of the above problems, there is a need for a kilt that allows full leg motion and natural ventilation for the wearer. There is an additional need for a kilt that does not "catch" or snag the wearer's kilt onto objects when walking, running, or otherwise engaging in physical activities. There is an additional need for a kilt that does not impede a wearer's line of sight when the wearer walks or runs."

Read the patent:

http://patft1.uspto.gov/netacgi/nph-...S=PN/6,282,723

It is a US patent, not an "international" patent, so it's tougher to inforce to people who make and sell similar garments STRICTLY outside the US.

Why can he patent a pleating system that's been used before him? He's the first one to apply for a patent on it... that's how.