A clinical AI model does not need to know who the patient is to reason clinically. It needs the symptoms, medications, lab results, diagnosis history, and treatment course. The problem is that in real medical records, those facts usually sit next to identifiers: names, record IDs, insurance numbers, addresses, phone numbers, admission dates, department names. So clinical de-identification has a double contract: 1. Do not let patient identifiers leak. 2. Do not destroy the clinical fac...