"A sweet, slightly musky, vanilla-like fragrance, with slight overtones of cherry, and a natural smell of a salted, wheat-based dough."
That's how Hasbro Inc., the major toy company that owns Play-Doh, describes the popular, pliable dough in its official application to patent the smell.
There are plenty of non-traditional things that have been trademarked, like sounds (Homer Simpsons "D'oh") and even shapes (the Oscar statuette). But when it comes to smells, it's tricky. You have to prove the scent is integral to your brand and recognizable to the greater public.
WNYC's Shumita Basu looks at the application process to trademark a scent.