7. The experts of the Informal Working Group “Simplification of the Lighting and Light-Signalling Regulations” (IWG SLR) reported on their activities and requested GRE to provide guidance on the following issues (GRE-91-03):

• Whether UN Regulations should refer to a specific revision (currently Revision 7) of the Consolidated Resolution on the Construction of Vehicles (R.E.3.) or a dynamic reference would suffice, and
• Whether the detailed description of an approval number in UN Regulations could be replaced by a reference to Schedule 4 of the 1958 Agreement.

8. Following an exchange of views, GRE agreed to seek advice on these points from the Coordination Committee (AC.2) and WP.29. The Chair said that he would submit a request to the forthcoming session of AC.2 in November and would report back to GRE at its next session.

9. The expert of IWG SLR also sought guidance on the principle “prohibited if not allowed” for the lamp installation according to UN Regulation No. 48 (GRE-91-02) and proposed three different options to incorporate this principle (GRE-91-22). Several experts from Contracting Parties expressed general preference for options A or C, but no final wording was agreed. GRE decided to revert to this issue at the next session. In the interim, experts were invited to send their comments to IWG SLR.