Optional concessional tax regime permits elective slab-based taxation with restricted deductions and adjusted loss treatment. Section 115BAC provides an optional concessional tax regime whereby eligible individuals, HUFs and certain other persons may elect to compute income-tax under specified slab rates. The option requires prescribed exercise and, once in force, applies to subsequent years unless invalidated by failure to meet conditions or withdrawn under limited circumstances. Under the regime, multiple exemptions and deductions are disallowed, certain loss set-offs and depreciation are barred or adjusted, and transitional adjustments to written-down values are required; specific modifications apply to Units in the International Financial Services Centre.