(1) The Commissioner must, in writing, determine the claim periods for each particular grant or benefit. The claim periods may be different for entities of a kind specified in the determination. (2) Despite subsection (1), the claim periods , for a particular grant or benefit, for entities of a kind in respect of which a determination under subsection (3) is in force, are the periods worked out in accordance with that determination. (3) The Commissioner may, in writing, determine the claim periods for a particular grant or benefit for particular entities specified in the determination.