Yes UNECE stands for United Nations Economic Commission for Europe formed in 1952 predating the Common Market and the EU. Now what you need to look at is the UN WP 29 to
Brendan
The World Forum for Harmonization of Vehicle Regulations is a working party of the Sustainable Transport Division of the United Nations Economic Commission for Europe. It is tasked with creating a uniform system of regulations, called UN Regulations, for vehicle design to facilitate international trade.
Brendan