Sheetrock is, in fact, a product name for Drywall/Wall board. Although it has passed into the common lexicon in the same manner as Kleenex, it is still a trademarked term. The registrant is the United States Gypsum Company of Illinois, who have 'owned' it since March of 1922; it underwent its most recent renewal in 1982, and will probably need another renewal in 2002.