When a receipt book has been used up, the tax collector shall return it to the Executive Officer who before issuing a fresh book shall see (1) that no page has been extracted and (2) that in the case of cancelled forms the original, duplicate and triplicate copies are in the book and have been cancelled. The unused forms of a party used book shall be cancelled by the Executive Officer across the forms to render them unfit for use. If any entire book of forms are unused they may be used in the next year.
