Backpacks for use by elementary and secondary students. A backpack is a pack with straps one wears on the back. The exemption during the sales tax holiday includes backpacks with wheels, provided they can also be worn on the back like a traditional backpack, and messenger bags. The exemption does not include items that are reasonably defined as luggage, briefcases, athletic/duffle/gym bags, computer bags, purses or framed backpacks. Ten or fewer backpacks can be purchased tax-free at one time without providing an exemption certificate to the seller.