Prospective
2Unless the circumstances appear to them to be exceptional—
(a)in a case where the Board have not previously awarded compensation in respect of an injury they shall not determine a claim in respect of it which is made after the end of three years from the date of the incident giving rise to the injury; and
(b)in a case where they have previously awarded compensation in respect of an injury, they shall not determine any further claim in respect of it which is made after the end of three years beginning with the date of the notice under paragraph 6(2) below relating to the award, or latest award, of compensation in respect of the injury.