First of all, only registered trademarks can use R. Secondly, registered trademarks have the right to add R when using trademarks, but they don't have to add R. Therefore, we can't judge the authenticity of goods simply by whether there is R. Moreover, counterfeiting is an infringement, and counterfeit goods must bear legal responsibility for printing R or not, so it is not necessary for counterfeiters not to print R.