Seat Cover Technology

When installing new car seat covers, I noticed they were asymmetrical and specified which side should be near the window with the label "airbag". Is there some design feature in the seat cover construction to specifically make it safe for use with side airbags? Or is it coincidental with the fact that the window side is the user approach side and will get more wear? Is there an ISO standard? I noticed similar airbag tag on a different brand seat cover installed on another car. If I install on an old car without side airbags, that should be safe from any side airbag incompatibility issues with the seat cover, right?