Net realisable value adjustments ensure inventories are carried at recoverable amounts, with write-downs and limited reversals under accounting rules. Inventories are carried at the lower of cost and net realisable value, calculated as estimated selling price less costs of completion and costs to make the sale; write-downs are generally made item by item, except where grouping of similar items is appropriate. NRV estimates must use the most reliable evidence at the measurement date, reflect the purpose for which inventory is held (including contract prices for firm sales), and consider post-period events only insofar as they confirm period-end conditions. Materials for production are written down only when finished-product NRV falls below cost. Each period requires reassessment and reversal of write-downs is limited to the original amount when circumstances change.