What does the letter after the motorcycle model displacement mean? (such as Honda CBR1000r)

Honda CBR 1000RRHONDA means that Japanese Honda Motor Company CBR is a family of Honda motorcycles. For example, CBR250CBR954CR means road racing engine is also a CBR series 1000 means 1000CC means 1 The displacement RR of 00 L means to highlight the performance of the racing car and if we compare the design of HRC CBR 100 RR, HRC means the racing car R&D team of Honda Company of Japan. It is a member of the Fireblade family designed by HRC to design various events such as GP races, and its performance is excellent!