Define the U.S. gold import point or the lower limit in the exchange rate (R = $/).

Question:

Define the U.S. gold import point or the lower limit in the (R = $/£). Why is this so?
Exchange Rate
The value of one currency for the purpose of conversion to another. Exchange Rate means on any day, for purposes of determining the Dollar Equivalent of any currency other than Dollars, the rate at which such currency may be exchanged into Dollars...