Part I of this paper defines key concepts and specifies how IFs and IRRs arise in genetic and genomic research involving biobanks. Part II identifies the core questions to be addressed in deciding how to manage IFs and IRRs. We describe how biobanks appear to be addressing these issues now, and argue that biobanks have a responsibility to make their approach to IFs and IRRs explicit, whether or not the biobank plans to return IFs and IRRs. We then address the design choice that biobanks face of irretrievably stripping identifiers versus preserving the possibility of re-identification and thus return of individual IFs and IRRs to contributors. For biobanks in which re-identification--and thus return--is possible, we progress to considering what responsibilities biobanks should shoulder and offer recommendations for how those responsibilities should be discharged. We analyze the core responsibilities using the organizing acronym CARR: (1) clarifying the criteria for evaluating findings (e.g., analytic validity, seriousness of condition, and actionability) and the roster of returnable IFs and IRRs; (2) analyzing a particular finding in light of those criteria and that roster to
