DVD players typically support "plus" and "minus" formats (read-only DVD+R and DVD-R and rewritable DVD+RW and DVD-RW); however, older players may play only the minus group (DVD-R, DVD-RW).

and you could walk into Circuit City and buy those tiny little DVD-Rs. But you couldn’t do it. You couldn’t burn GameCube games, at least without advanced soldering skills. One company did.