AutoFormatExpr

When you use the AutoFormatType and AutoFormatExpr properties to format a field, a trigger called AutoFormatTranslate in CodeUnit 1 is called. AutoFormatTranslate has ID 12 and takes two parameters; one from the AutoFormatType property and one from the AutoFormatExpr property. The AutoFormatType property contains an integer (0, 1 or 2) and the AutoFormatExpr property contains text (“ =LCY”).

...
CASE AutoFormatType OF
  1: // Amount
    IF AutoFormatExpr = '' THEN
      EXIT(STRSUBSTNO(Text012,GLSetup."Amount Decimal Places"))
    ELSE BEGIN
      IF Currency.GET(AutoFormatExpr) AND (Currency."Amount Decimal Places" <> '') THEN
        EXIT(STRSUBSTNO(Text012,Currency."Amount Decimal Places"))
      ELSE
        EXIT(STRSUBSTNO(Text012,GLSetup."Amount Decimal Places"));
    END;

  2: // Unit Amount
    IF AutoFormatExpr = '' THEN
      EXIT(STRSUBSTNO(Text012,GLSetup."Unit-Amount Decimal Places"))
    ELSE BEGIN
      IF Currency.GET(AutoFormatExpr) AND (Currency."Unit-Amount Decimal Places" <> '') THEN
        EXIT(STRSUBSTNO(Text012,Currency."Unit-Amount Decimal Places"))
      ELSE
        EXIT(STRSUBSTNO(Text012,GLSetup."Unit-Amount Decimal Places"));
    END;
  10: EXIT('<Custom,' + AutoFormatExpr + '>');
END;