Article 79 delegates the determination of rules for capital assets held under finance leases to the Executive Regulations. It mandates that these rules must ensure leased assets are treated in accounts according to International Accounting Standards (IAS) or similar standards approved by the Chairman of the Tax Authority. This provision allows Oman's tax law to keep pace with evolving financial lease structures, ensuring that the 'substance over form' principle applies so that entities effectively controlling an asset under a finance lease can claim appropriate capital allowances in line with global financial standards.