TF 3c addressed brake emission of replacement parts. Proposed amendments include clarification that surface heat-treated discs fall under “other” category, refinement of “Brake Emissions Family Parent” definition, and addition of new appendix to UN Regulation No. 179 Annex 2. Data sharing agreement established: front-to-rear axle emission ratio, brake force distribution, and vehicle electrification type will be shared with aftermarket operators. Two approaches for aftermarket applicants: use vehicle-specific data through benchmarking or bilateral agreements, or apply default values from Tables 5.4 and 5.5. Testing revealed up to 30% variation within friction-couple families. Safety factor application when using actual c-factor values remains under discussion, with final decision expected before October.