36. GRSG recalled that its experts were invited to provide further comments and indications on which UN Regulations would not be affected by Unique Identifier (UI). GRSG also noted that it was expected to complete the tentative list provided in GRSG-124-21 distributed at its October 2022 session (ECE/TRANS/WP.29/GRSG/103, paragraph 31).

37. The expert from the Netherlands, secretary of IWG DETA, clarified that the unique identifier is a number generated by the DETA database, and allocated to a type approval when uploaded to the database. He added that the UI number may also be used by the manufacturer as product marking, and that the traditional E marking may be replaced by this UI mark. However, he clarified that some UN Regulations required additional marking information. He added that when traditional marking was replaced by UI marking, this additional marking would be potentially removed. However, he noted that this information could be needed for surveillance or periodical technical inspections (PTI) purposes. Accordingly, WP.29 agreed to request its subsidiary bodies to screen all UN Regulations to find if the E marking could be replaced by the UI marking. If any UN Regulation allows replacement, he informed GRSG that WP.29 had proposed a template (WP.29-188-20) to indicate which additional marking information shall remain on the product. He also underlined that UI marking was primarily of benefit for automotive component industry (large markings on small components) while for contracting parties no benefit was provided.

38. The expert from CITA introduced GRSG-125-35 (based on WP.29-188-20) listing all UN Regulations under the purview of GRSG providing information that his organization deems relevant. The expert from OICA argued that the document diverted from the general use of UI as agreed by WP.29: (a) UI shall be applied by default, only exceptions may prohibit it, (b) from UI, PTI can retrieve all the necessary information and (c) some markings were too large on safety glazing thereby compromising light transmittance requirements. The expert from CITA mentioned that E marking provided instant information while UI was time consuming and added extra costs to PTI. He argued that glazing is large enough to host E markings and should be checked frequently because of frequent replacement. Therefore, even in this case he saw the UI solution as time and resource consuming. The expert from the Netherlands suggested that concerned parties had learned much about the use of UI since its establishment by way of the Revision 3 of the 1958 Agreement. Moreover, he suggested that the complexity introduced by UI led to rethinking its use. The expert from the United Kingdom suggested that GRSG-125-35 was a useful document. However, he insisted that this screening needed a coordinated and consistent position and use throughout all the subsidiary bodies of WP.29. The expert from Germany expressed sympathy for GRSG-125-35, however he requested a time reservation. The Chair of GRSG stated that he would inform WP.29 that GRSG-125-35 represented the opinion of the expert from CITA and that GRSG retains a further revision of GRSG-125-35. GRSG agreed with the suggestion of its Chair, to resume discussion at its October 2023 session and to keep GRSG-125-35 as an informal document.