The secretariat of the World Forum for the Harmonization of Vehicle Regulations has posted helpful lists of acronyms and symbols used in UN Regulations. This listing grew out of concerns that different regulations use the same acronym for different terms (e.g., HPC for head performance criterion and hybrid powertrain cycle) which might cause confusion. The lists of acronyms and symbols can be found at www.unece.org/trans/main/wp29/wp29wgs/wp29gen/acronyms_definitions.html
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