17. As noticed earlier, the drawback claims in all these petitions relate to the period between December 1995 to 1996, in relation to which, show cause notices came to be issued in February 2000. Thus, in all the cases, drawback claims had been processed and cleared before issuance of the clarification vide letter dated 20th September 1996 by the Commissioner (Drawback) with the approval of the Chairman of C.B.E. & C. On a close reading of the said letter, it is apparent that the same envisages finalization of pending drawback claims in the light of the clarification issued therein, namely, that the maximum ceiling has to be inferred even in cases where goods are not exported under AR and/or exporter is unable to furnish the certificate as required under condition (b) of the Note to SS No. 5404 (1) in respect of which drawback is payable at the rate of 17% of the FOB value. Thus, while issuing the initial clarification on 20th September 1996, the instructions issued by the C.B.E. & C. were to the effect that the same should be applicable only to pending drawback claims. Subsequently, by the clarification issued vide letter dated 19th August 1999, C.B.E. & C. clarified that the earlier clarification of 20th September 1996 was operative from the date of issuance of the original notification and was not only prospective. It appears that it is only pursuant to the subsequent letter dated 19th August 1999, that the show cause notices have been issued in February 2000. Thus, though the Customs Authorities were well aware about the clarification in respect of the drawback paid on goods falling under condition (c) of the Note below sub-serial No. 5404 (1) of the Schedule, no action was taken at the relevant time to recover the drawback paid to the petitioner beyond the ceiling limit provided thereunder. It is only in February 2000, after a period of more than three years that by issuance of show cause notices, differential amount of drawback was sought to be recovered from the petitioners. The revisional authority in the earlier order dated 28th June, 2002 has held that the Drawback Rules do not provide for any time limit and as such there is no time limit for issue of demand notice for recovery of drawback paid erroneously or in excess under rule 16 of the Rules.