These Regulations amend the Hydrocarbon Oil (Marking) Regulations 2002 (S.I. 2002/1773) (“the principal Regulations”) and the Hydrocarbon Oil (Designated Markers) Regulations 1996 (S.I. 1996/1251) (“the designated markers Regulations”). There are amendments concerning the requirement to add a new marker, n-butyl phenyl ether, to oil, bioblend and biodiesel as a condition of the rebate of fuel duty on these products and other amendments concerning fuel marking and colouring.