12. GRE noted a request of the Informal Working Group for Electronic Database for the Exchange of Type Approval documentation (IWG DETA) to provide clarity on the UN Regulations for which the Unique Identifier (UI) markings may be applied (GRE-88-02-Rev.1 and GRE-88-03-Rev.1). The expert from the International Motor Vehicle Inspection Committee (CITA) recalled its previous position on the need for additional markings in case of UI, to ensure the availability of sufficient information on the device for periodic and roadside inspections (ECE/TRANS/WP.29/GRE/2022/13, GRE-87-07). Some experts pointed out that additional markings would run counter the very idea of UI.

13. To review UN Regulations under its purview for the purposes of UI (GRE-88-26), GRE made the following classifications:

1. Obsolete device UN Regulations that had been frozen in the course of two freezing exercises;
2. New simplified device UN Regulations Nos. 148, 149 and 150;
3. Installation UN Regulations Nos. 48, 53, 74 and 86;
4. Light sources UN Regulations Nos. 37, 99 and 128; and
5. Standalone UN Regulations Nos. 10, 45 and 65.

14. GRE agreed that UI could be used for the group (b) above, but definitely not for (a) and probably not for (c) and (d). For the group (e), GRE invited IWG SLR and the Informal Working Group on Electromagnetic Compatibility (IWG EMC) to prepare recommendations. Finally, GRE decided to revert to this topic at the next session, including the issue of additional markings.