This chapter turns to the second step of interpretation, namely content-determination. This exercise can be narrated in two ways: first, by reference to the formal rules of interpretation set forth in the VCLT; second, in light of the assumptions, predispositions, and standards of acceptability shared by the judicial community. The juxtaposition of these accounts highlights the interplay between freedom and constraint in international treaty interpretation. What guides the gaze of the interpreter? Where are the boundaries of their discretion? On the one hand, VCLT rules are powerless before the ontological indeterminacy of legal norms, and have therefore little cash value when it comes to derive exact meaning. On the other hand, the patterned practices and background knowledge of the community impose powerful limitations on the interpreter’s discretion.