31. The expert from the Netherlands, secretary of IWG DETA, introduced GRSG-124-15, recapping the examples that explain where a Unique Identifier (UI) marking could be used. The expert from CLEPA introduced GRSG-124-21, reproducing a first screening of UN Regulations annexed to the 1958 Agreement focusing on component related UN Regulations and on UN Regulations requiring additional markings to the approval markings. He added justifications for the prohibition of UI in UN Regulations Nos. 43 (Safety glazing) and 55 (Mechanical coupling). The expert from Finland, recalled to GRSG the position of the Working Party on Lighting and Light-Signalling (GRE) at its April 2022 session: for an efficient application of UI in the context of simplified UN Regulations, a summary document should be made available in DETA and that a template for the summary document should, as soon as possible, be introduced into these UN Regulations by means of a Supplement (ECE/TRANS/WP.29/GRE/86, paragraph10). The expert from CITA agreed with the position of the expert from CLEPA. He also added that UN Regulations Nos. 46 and 58 should exclude the introduction of UI and announced a document for the March 2023 session of GRSG that provides justification for implementing UI only when it is explicitly requested and in evidence of a clear advantage. GRSG agreed to resume discussion at its March 2023 session on the basis of the principle agreed by WP.29 that any prohibition of UI be clearly specified in the concerned UN Regulation. GRSG experts were invited to provide further comments/indications on which UN Regulation would not be affected by UI to complete the tentative list provided in GRSG-124-21.