Marketmakers , who are responsible for providing liquidity in trading situations , must often take naked short positions when there is more demand for a stock than supply 做市商们有必要为了满足未来对股票的需求而持有一些光票空头头寸，这样做有益于保持市场的流动性。
A in respect of clean collections , partial payments may be accepted if and to the extent to which and on the conditions on which partial payments are authorised by the law in force in the place of payment 第十九条：部分付款1光票托收时，只有在付款地现行法律准许部分付款的条件和限度内，才能接受部分付款。
The buyers shall open through a bank acceptable to the sellers an irrevocable sight letter of credit to reach the sellers * * days before the month of shipment , stipulating that 50 % of the invoice value available against clean draft at sight while the remaining 50 % on documents against payment at sight on collection basis 买方应通过以卖方所接受的银行于装船月份前* *天开立并送达卖方不可撤销即期信用证，规定50 %发票金额凭即期光票支付，其余50 %金额用即期跟单托收方式付款交单。
Chapter i makes detailed delineation of the definition and characters of the standbys with its focus on the comparison between several concepts : standby vs . clean l / c , standby vs . commercial documentary l / c , standby vs . surety and standby vs . banker ' s guarantee . based on the comparison , i give prominence to the nature of the standbys , thus laying foundation for the two chapters thereafter 本文第一章对备用证的定义和性质进行了详细介绍，重点比较了备用证与光票信用证、商业跟单信用证、保证和银行保函的异同，澄清了容易混淆的几组概念，突出了备用证的特点，为后两章的规则比较打下了基础。
