Fair market value rules define asset-specific valuation methods and currency conversion for undisclosed foreign assets. Rule 3 prescribes that fair market value is generally the higher of cost of acquisition (or amount invested) and open market sale price on the valuation date, with specific valuation methods for bullion, artistic works, quoted and unquoted shares and securities, immovable property, bank accounts, and interests in firms or LLPs. It provides a formula for unquoted equity shares, allocation rules for net assets of partnerships, conversion protocols for foreign currency valuations, and adjustments where assets were transferred before the valuation date or proceeds reinvested in new assets.