The currency string used in currency display functions SysUtils unit
  var CurrencyString : string;
The CurrencyString variable is used in currency display functions. It is used to prefix or suffix the currency amount.
For example, the UK default is ?, so 1.23 is displayed as ?1.23 by default.
The CurrencyFormat value determines whether the currency string is placed before or after the amount, and whether a space is placed between it and the amount.

CurrencyString = LOCALE_SCURRENCY by default.
Related commands
CurrencyDecimals Defines decimal digit count in the Format function
CurrencyFormat Defines currency string placement in curr display functions
CurrToStrF Convert a currency value to a string with formatting
DecimalSeparator The character used to display the decimal point
Format Rich formatting of numbers and text into a string
NegCurrFormat Defines negative amount formatting in currency displays
ThousandSeparator The character used to display the thousands separator
Example code : Changing the currency character to a word
  amount : Currency;

  amount := 12;    // 12 pounds

  // Display with the default currency string
  ShowMessage('Amount = '+CurrToStrF(amount, ffCurrency, 0));

  // Display with the currency shown as a word after the amount
  CurrencyString := 'Pounds';
  CurrencyFormat := 4;    // 4 means after with a space
  ShowMessage('Amount = '+CurrToStrF(amount, ffCurrency, 0));
Show full unit code
   Amount = ?12
   Amount = 12 Pounds