R.1 .

       In the said Rules, in Rule 14, in sub-rule (4), for clause (a), the following clause shall be substituted, namely:
       (a) Payment shall ordinarily be effected only on completion of delivery against the orders placed:
       Provided that payment of advance may be made in the following cases for sufficient reasons to be recorded by the procuring entity:
       (i) in cases where goods, commodities and services are procured through imports requiring opening of Letter of Credit;
       (ii) in cases where there is single source of supply only and where the practice of paying advance is already in vogue as a standard practice;
       (iii) in cases of purchase during natural calamities and emergencies declared by the Government under claus