  The frequency dependence of the Raman coupling coefficient $C(\omega)$ is
calculated numerically for square and cubic percolation clusters. No general
scaling law in terms of the macroscopic parameters such as the fractal
dimension $D$ or the spectral dimension $\overline d$ is found. $C(\omega)$ is
sensitive to the microscopic structure of the clusters and depends on: site- or
bond-percolation, presence or absence of dangling bonds, scattering mechanism
and polarization, presence or absence of polarizability disorder. This
situation makes the derivation of macroscopic parameters from Raman experiments
unreliable.
