Division 3.2.7.1 Up to 31 December 1999 ; either as prescribed in paragraph 3.2.7.2 or in the form of a group of three digits, the first two showing the week number and the third, the year of the decade of manufacture. The date code can cover a period of production from the week indicated by the week number up to and including the week number plus three. For example, the marking ‘253’ could indicate a tyre which was retreaded in weeks 25, 26, 27 or 28 of the year 1993.F1