Income Computation and Disclosure Standards apply to business and other income, with exclusions, disclosure duties, and Act precedence. ICDS notified under section 145(2) apply from assessment year 2017-18 to taxpayers computing income under business or profession and income from other sources, subject to specified exclusions including non-audit individuals and HUFs, presumptive taxation cases, and MAT. The standards require adjustments to financial statements, disclosure of net effect in the return and Form 3CD, and apply only to income computation under the specified heads. They do not govern other Act purposes such as TDS timing, and the Income-tax Act prevails where there is any conflict.