Whether cakes and biscuits go hard or soft when stale helps to determine whether they are indeed cakes or biscuits (cakes go hard, biscuits go soft). This is the difference between VAT at 20% and zero rating for some products.
Whether printed matter is stiff or floppy can also result in either 20% or zero rated treatment. In this case, for single sheet products, eg; leaflets; limp is good and hard can result in the VAT hit.
What did you think I was talking about? Stop making up your own jokes…