Draft proposal to introduce into Regulation No. 48 a definition and general requirements for usage of a “change index” established by the new simplified Regulations on Light-Signalling Devices (LSD), Road Illumination Devices (RID) and Retro-Reflective Devices (RRD). The “change index” indicates the number of times new series of amendments have posed higher stringency requirements to a specific lamp (function) under these regulations.