If you keep multiple open positions of the same size and same currency pair, this new trading policy may mean important changes to how you manage these trades. (oanda.com)
I can only buy and sell in same currency only, albeit sell (buy) in the same exchange where I buy (sell) from. (money.stackexchange.com)
Not valid for same currency wire transactions (e.g. US Dollar to US Dollar). (americanexpress.com)