In addition to the interests of the drawer, drawee, acceptor, purchaser, and the party to whom the letter of credit is issued and his guarantor, the general public has an interest in the actual and contingent liabilities undertaken by the banks. These obligations, if recklessly assumed, may seriously affect the banking situation. In old banks experienced in the acceptance business, and in banking communities which exercise a mutual guardianship and restrain excessive accepting by any bank, the danger is small; but when experience in this field of banking is lacking and where banking policy is conservative and sound in other respects primarily because of a severe system of bank supervision, the state may find it necessary to put restraints on the free exercise of the acceptance power. By limiting a bank's power to accept only such bills as arise out of the importation and exportation of merchandise or other such commercial transactions, a very definite limit is put to the extension of this sort of credit. Also if the total amount of acceptances outstanding at any one time is limited to some percentage of the capital and surplus of the bank, the liability can be kept within safe bounds. A third method is to limit the aggregate amount of acceptances bearing one drawer's name, thus distributing the risk. The United States government restricts the acceptance powers of national banks in these ways.