(1)Any citizen who, on the day prior to the date of commencement of this Act, had attained the age of fifteen years but had not attained the age of sixteen years and was therefore not a person liable to registration under subsection (1) of section 2 of the principal enactment and on such date becomes so liable by virtue of the provisions of that section as amended by this Act, shall be deemed not to be guilty of an offence under section 44 of the principal enactment, provided that such person makes an application within the prescribed period for such registration under the provisions of that enactment.