Depreciation under income tax law sets mandatory asset-wise allowance rules for business assets and intangible rights. Depreciation under the Income Tax Act is an allowance on capital assets acquired and put to use for business or profession, and not an expenditure. It applies to owned tangible and intangible assets, with proportionate allowance where use is not exclusive for business. Depreciation is mandatory from assessment year 2002-03 and is allowed or deemed allowed irrespective of a claim in the profit and loss account. The schedule prescribes written down value rates for block of assets, with special rates for power generating units, specific industrial machinery, renewable energy devices, computers, ships and intangible assets.