Institutions do not encounter novelty with empty hands; they classify it through categories built for what they already know. A new practice entering a university, museum, funding programme or disciplinary journal is therefore translated before it is judged: its unfamiliar features are recoded as versions of established ones so that existing procedures can process them. This translation can make novelty legible, but it can also erase exactly the differences that made the new formation necessary. OpaqueLegitimacy names the gap produced when a new practice functions coherently but inherited institutional categories can register only a partial version of it. The problem is not that inherited categories are useless; institutions need comparability to function. The problem begins when comparability is mistaken for identity and the institution recognises only the portion of novelty that already resembles its past.