51. GRSP noted the excel files, that are permanently appended to its website, for the abbreviations and symbols of UN Regulations and UN GTRs (www.unece.org/trans/main/wp29/wp29wgs/wp29gen/acronyms_definitions.html). The Chair of GRSP announced the preparation of an informal document for the December 2016 session of GRSP gathering acronyms and definitions present in UN GTR in cooperation with the Chairs of IWGs, to revise the document and provide comments to the secretariat.