Proposal to

1. 1. Add a generic reference to the Consolidated Resolution on the Construction of Vehicles (R.E.3) in footnote 1
2. Make editorial corrections to the type of tyre and additional service description definitions
3. Clarify the definition of nominal rim diameter (in line with the proposal for amending UN R30)
4. Amend the definition of principal grooves (in line with the proposal for amending UN R30
5. Introduce a definition for tread depth (used in the requirements for special use and professional off-road tyres)
6. Introduce definition for free rolling tyre and front axle, and related revision of markings (ref. GRBP-80-03 and GRBP-80-26)
7. Clarify the D_max requirement for snow tyres
8. Simplify rhz wording of the requirements for professional off-road tyres
9. Add an indication for whether a special use tyre is a professional off-road tyre to the communication form (in line with UN R30).