Principles of protein structure and function -- A brief history of protein disorder -- Indirect techniques for recognizing and characterizing protein disorder -- Hydrodynamic techniques -- Spectroscopic techniques for characterizing disorder -- Nuclear magnetic resonance -- Proteomic approaches for the identification of IDPs -- IDPs under conditions approaching in vivo -- Prediction of disorder -- Structure of IDPs -- Biological processes enriched in disorder -- Molecular functions of disordered proteins -- Evolution and prevalence of disorder -- Extension of the structure-function paradigm -- Structural disorder and disease