The reflection implemented in SWAN version 40.11 is just specular reflection. It gives the mirror image of the action density spectrum, cutting it off for all directions that are not directed towards the obstacle and multiplying it by the reflection factor C_r^2 (square because the reflection factor is w.r.t. wave height). To improve the performance of the reflection in SWAN, a small study was made on what is known from literature. Further, some analogy is made with the field of optics, concerning diffuse reflection and scattered reflection effects. To avoid confusion: only reflection at obstacles is considered here. The scattered reflection or scattering that is discussed here is NOT what civil engineers may call Bragg scattering.