Promoters' contribution eligibility limited for securities acquired via revaluation, bonus issues, low price acquisitions, allotments, or pledges. Regulation 33 excludes specified securities from calculation of promoters' contribution where they were acquired for non cash consideration involving revaluation or capitalisation of intangibles, resulted from bonus issues financed by revaluation reserves or unrealised profits, were pledged with creditors, or were acquired/allotted within prescribed lookback periods at prices below the IPO price; limited exceptions permit eligibility if price differences are paid to the issuer, if securities arise from a court approved reorganisation substituting longstanding invested capital, if predecessor capital preexisted continuously, or for certain government or infrastructure vehicle IPOs.