IEC 62056-6-1:2017 specifies the overall structure of the OBject Identification System (OBIS) and the mapping of all commonly used data items in metering equipment to their identification codes. This third edition cancels and replaces the second edition of IEC 62056-6-1, published in 2015. It constitutes a technical revision. The main technical changes with respect to the previous edition are listed in Annex B (informative).