It is worth noting that a wrong folkoric definition of an Inertial Frame in the Popular Science literature (even in text books) reads that 'it is a frame in uniform motion'. We know very well by now that the idea of motion requires a frame of reference, so that such a definition of an Inertial Frame has no meaning whatsoever, confusing the reader because it tacitly reaffirms the idea of absolute motion -- when the goal of every didactic exposition of Relativity Theory should be precisely the opposite.