At the request of the Decennial Management Division (DMD), staff from the Statistical Research Division (SRD) led an interdivisional team to develop and cognitively pretest new confidentiality language embedded in the mailing package for the 2008 Census Dress Rehearsal. Once developed, the intent was to include these messages in the 2010 Census mail materials. In particular, the team (or “working group”) was given the task of developing new confidentialityand privacy-related messages for the decennial mailing package, namely, the main confidentiality statement and supporting concepts. The supporting concepts either modify or describe how the data will be treated and/or used (i.e., to produce statistics and/or to study and improve process-oriented production efficiency), and how the data may be augmented by records housed within other federal agencies—concepts commonly referred to as “statistical purposes” and “administrative records use” within the Census Bureau. The Working Group was responsible for identifying the main components of these concepts, in order to communicate them to respondents in plain language, and developing these ideas into a cohesive confidentiality message that would be embedded in a respondent cover letter to the decennial questionnaire.