The different secondary structure elements in (poly)peptides, including intrinsically disordered ones, produce specific responses upon light excitation. The experimental CD, FT-IR, Raman and ROA spectroscopic fingerprint of our model peptide in water is reported in Fig. (cf. ESI for experimental details). The different signals prove that the peptide is mostly disordered, with some deviations that are consistent with a minor, but important amount of ordered microstates in the conformational ensemble.