Suggestions:
A Sales quotation document contains an itemized list of items and services defining the prices and terms of sale and payment. Usually this document is sent at the request of a prospective buyer who is interested in knowing the cost of certain products or services. Once the quote has been accepted, the customer is committed to making a Purchase at the stated price.
In quotation documents, Exchange Rate is the currency to base currency. Default is taken from the currency master and is mandatory. Exch. rate gets set from Daily Exchange Rate, it can be edited if required.