Expert Advisor Programming by Andrew R. Young

Tips and Tricks
Using Order Comments As an Identifier
We've been using the "magic number" as an order identifier that uniquely identifies orders as being
placed by a particular expert advisor. If your expert advisor places multiple orders at one time, and
you want to be able to handle each of those orders differently, you can use the order comment as an
optional identifier.
For example, lets say your expert advisor will place two types of orders. You want to be able to
modify or close these orders separately. You'll want to use two OrderSend() functions and place a
different order comment with each one. Then, when selecting orders using the order loop in chapter
5, you'll use OrderComment() as one of the conditions for locating orders to modify or close.
string OrderComment1 = "First order";
string OrderComment2 = "Second order";
// Order placement
int Ticket1 = OrderSend(Symbol(),OP_BUY,LotSize,OpenPrice,UseSlippage,BuyStopLoss,
BuyTakeProfit,OrderComment1,MagicNumber,0,Green);
int Ticket2 = OrderSend(Symbol(),OP_BUY,LotSize,OpenPrice,UseSlippage,BuyStopLoss,
BuyTakeProfit,OrderComment2,MagicNumber,0,Green);
// Order modification
for(int Counter = 0; Counter