IAS 16 allows companies to choose between the cost model and the revaluation model for the subsequent measurement of property, plant and equipment (PPE). However, if a company chooses to revalue its PPE, IAS 16 imposes some restrictions on revaluation.

1. List the restrictions IAS 16 imposes on revaluation.
2. Why does IAS 16 impose these restrictions on revaluation?
3. Briefly explain whether revaluation of PPE is useful to users.