Over the past decades and more recently, there has been a significant effort and renewed interest in extending special relativity theory beyond the speed of light. In this comprehensive note, the paper "Relativity of superluminal observers in 1+3 spacetime" by Dragan et al.[1] is examined. The authors attempted to extend the aforementioned theory to superluminal inertial reference frames by generalizing Parker’s two-dimensional transformation with the addition of two pairs of spatial dimensions. This approach is not novel and is already well-documented in the literature. It is demonstrated that unlike Lorentz transformations, the authors’ transformations do not form an orthogonal-orthochronous group due to their negative determinant. Consequently, principles such as relativity, causality, spatial isotropy, and temporal ordering cannot be preserved. The authors’pseudo-transformations are revealed to be reflections in a plane through the origin rather than true transformations. Also, a theoretical maximum limit of the Lorentz factor is introduced, which leads to an extension of Lorentz transformations to luminal inertial reference frames and raises an important conceptual question about the status and role of the symbolic quantity ‘c’, commonly called the speed of light in vacuum, as the neutrino and particularly the photon have non-zero mass. Therefore, it appears that as long as the non-zero mass of the photon is not taken seriously into full consideration, our current knowledge of physics, astronomy, astrophysics, and cosmology remains not only incomplete but above all vague and doubtful. Unfortunately, it seems that many present-day researchers are unaware that distinguished physicists like Einstein [59-62], de Broglie [63-66], Proca [67-71], Schrödinger [72-74], and many others [75-92] had already attributed non-zero mass to the photon because they realized that the photon itself behaves like a massive particle, carrying not only energy but also momentum and can exert pressure on a target. And at no stage may we really be able to conclude experimentally the exact masslessness of the photon because the Heisenberg uncertainty principle gives the lowest mass m that can be measured in the Universe’s age as m~ℏt^(-1)c^(-2)~1.5×10^(-33) eV/c^2. Once again, therefore, non-zero photon mass gives rise immediately to a conceptual question: What is the primary purpose of the symbolic quantity ‘c’ when it appears in some important equations describing the laws of physics? Moreover, this inclusive note highlights Hassani superluminal spatio-temporal transformations, which possess the algebraic structure of a linear group and serve as a generalization of Lorentz transformations for superluminal inertial reference frames. These transformations are anticipated to be fundamental in superluminal relativistic mechanics [50].