Tight fitting, if not slightly long, nylon pants. Often with excess of 8 pockets/zippers, parachute pants were rampant in the Eighties. They were brought back to the market sometime in the mid-Nineties as 'Nylon Jeans'. Parachute pants are often mistaken for Baggy or poofy 'MC Hammer-esque' pants, which in actuality are known as ASTRO-pants.
Skariachi saxophonist/singer Kole 'Flash' Maravilla is a large supporter of the Parachute pants.
Rock Band + Horn Section = Ska. If singing is in a monotone (i.e. Streetlight Manifesto) and not have anyon notice or care because the bass kicks, the guitar is hot like fire, and the horn section is just plain better than everything else combined, you might be Ska. Also, if there are more than 5 people, it's a good indicator of ska.