S.28(i) : Business income-Accrual-Real income theory-Royalty-Mere deduction of TDS does not conclusively establish accrual of royalty income where ultimate collection is uncertain-Revenue recognition can be postponed under AS-9 where collectability is doubtful-Addition of royalty as undisclosed professional income deleted-However, amount of TDS claimed as credit deemed as income under section 198 and taxable-Relief restricted to royalty amount minus TDS claimed.[S. 5, 145, 198, 199, R. 37BA]