Have a look at the enclosed picture. The port set of numbers is lower and they are above the second batten and in line with rule 30.5 & 6. Spacing to the leach is not specified but numbers are usually placed close to the leach.
30.5 Emblem. Shall be shown on both sides of the mainsail. To be in accordance with the official drawings (a stylised W, with its
wing trailing towards the leech of the mainsail). On white sails the class emblem shall be red, and on other coloured sails of
contrasting colour to sail.
30.6 Sail numbers on mainsail. Shall be shown on both sides below the class emblem and above the upper of the two lower battens.
The numbers shall be of contrasting colour to the sail and not less than 300 (11¾”) in height, nor 200 (7.7/8”) in width (except for
numeral 1) nor 45 (1¾”) in thickness.