Despite many peer-reviewed works that draw on tobacco industry documents that have now been made public, questions remain about how complete a picture has emerged. We present a conceptual framework that identifies and evaluates tobacco industry efforts to conceal information. Widespread document destruction like that in recent litigation in Australia is just one of more than a dozen tobacco industry efforts to prevent access, or at least timely access, to documents. Industry efforts range from small, locally employed initiatives to company-wide tactics. Some efforts, such as using "oral only" procedures, scrambling telephone lines, or involving lawyers in scientific projects, are preemptive. Others seek to deal with already existing documents by invoking bogus claims of legal privilege, stipulating "read then destroy" for memos, and rewriting problematic memos. That evidence of concealment has, in fact, been found in tobacco company archives attests to the futility of attempting to control the flow of millions of pieces of paper among tens of thousands of employees. However, researchers have yet to reveal the full story: We know of the industry's failures in concealing information, but not its successes. The industry's objective is not destruction of information per se, but prevention of public disclosure of that information. Exposing the tobacco industry's many approaches to concealment provides greater insight into companies' intentions and potential means for stripping away that concealment.