The modern Raman spectroscopy is based on the photons scattered by a sample when a laser light shines on it. In the inelastic scattering processes, the emitted photons have a frequency shift, the Raman shift, which is producing the "fingerprint" typical of the investigated material. To the best of my knowledge, the first use of the term "fingerprint" for Raman spectroscopy was in the article by , about the Raman spectra of hydrocarbons. From that time on, the points of identification, such as the positions of peaks, shoulders and valleys have been considered to constitute the characteristic spectral pattern, that is, the "fingerprint" of a given material. For the carbon-based materials, the Raman spectroscopy is "a particularly well-suited technique" , due to the "long-range crystalline vibrations and short-range molecular vibrations of carbon species", which are producing, for the different materials, their characteristic spectral fingerprints. According to Zhang and coworkers, these fingerprints allow identifying the "specific carbon materials including graphite, diamond, graphene, carbon nanotubes, fullerene, and amorphous carbon". To these materials, we must also add the recent studies on "graphene, bilayer graphene, and two-dimensional graphene heterostructures" .