Proposal prepared by the GRSG Secretariat pursuant to discussions of document GRSG/2016/24. The proposal aims to improve and clarify provisions concerning the approval of interior materials, cables and insulation materials. The proposal adds new requirements for cable sleeves and conduits, modifies vertical testing requirements under Annex 8 to allow testing of small test samples and to clarify their fixation to the specimen holder., and adds a new Annex 10 on provisions for testing of electrical cables.