The word 'Shall' has the following meanings: An imperative command; has a duty to or is required to. For example, the notice shall be sent within 30 days. Usually 'shall' used here is in the mandatory sense.
译文：The total contract value shall be paid in USD, through ABCD BANK (Hereinafter referred to as “Buyer’s Bank”) and the commercial bank appointed by the Seller (Hereinafter referred to as “Seller’s bank”).
注释：法律英语（商务合同）中“下称” / “以下简称”翻译成：hereinafter referred to as。举个例子：
出租方(甲方) Lessor (hereinafter referred to as Party A) ：
承租方(乙方) Lessee (hereinafter referred to as Party B) ：
In accordance with relevant Chinese laws, rules and regulations ,Party A and Party B have reached the agreement through friendly consultation based on the principle of equality and voluntariness.
译文：40% of the total contract price shall be paid by Telegraphic Transfer within 15 days after the buyer has received the following documents and check them。
译文：The buyer shall，throug the buyer's bank within 20 days after the down-payment open an irrevocable L/C covering 60% value of contract in favor of the sellers and payable against the following documents。
拓展学习：down payment ：首付款; 定金; （分期付款的)首期付款; 预付金
英文释义为：If you make a down payment on something, you pay only a percentage of the total cost when you buy it. You then finish paying for it later, usually by paying a certain amount every month.
If you're borrowing money for the down payment, provide a copy of the entire loan agreement. 如果你要借钱付首付的话，要提供一份完整的贷款协议副本。
凭单据付款：payable against documents，信用证用语中都是against 这个介词表示：凭借。举个例子：
We usually accept payment by irrevocable letter of credit payable against shipping documents.