Derecognition of property, plant and equipment: gains or losses recognised in profit or loss, disposal date follows revenue recognition criteria. Impairment of property, plant and equipment is assessed under Ind AS 36, with compensation from third parties recognised in profit or loss when receivable. Impairment events, derecognition, compensation and replacement purchases are separate events accounted for under the relevant standards. Derecognition follows sale recognition criteria in Ind AS 115 for disposal date; gain or loss equals net disposal proceeds less carrying amount and is included in profit or loss. Under the revaluation model, any remaining revaluation surplus on disposal is transferred to retained earnings. Assets sold routinely after rental are transferred to inventories and revenue recognised under Ind AS 115.