(1) To mention reference : The date and reference number of reply to inquiry letter should be mentioned in the order letter and the remark should be made that order is being placed keeping in mind the terms and conditions mentioned in that reply letter.
(2) Specific Order form: If the seller has sent any order form along with reply to inquiry letter, then order should be placed in that order form only. The covering letter can be atteched with it.
(3) Instruction for goods : The Quantity of goods for which order is being Placed should be clearly mentioned, wich can be in Kilograms, grams , liter, meters, inches, cms, etc. Order letter without such information can not fulfill its purpose.