Section 109(ii) in The Central Government Account (Receipts and Payments) Rules, 1983
(ii)Every sub-voucher which under the provisions of rules 111 (sub-rule 3), 113, 119 and 120 is not forwarded either to the Accounts Officer or to a controlling officer along with bills but is recorded in the office to which the expenditure relates, must be duly cancelled by means of a rubber stamp or by an endorsement in red ink across the voucher, the cancellation being initialled by the officer authorised to draw the contingent bills of the office. The cancellation should be made at the time when the contingent bill in which the sub-vouchers are included is actually signed. If the amount of the sub-voucher exceeds the permanent advance, the cancellation should be made as soon as the payment is made and entered in the contingent register.
