15.3.3.4 Negative Fields
  To allow for a field containing negative values, you must
  place a trailing minus sign in the format field. A negative
  format field causes the value to be printed with a trailing mi-
  nus sign. You can also denote negative fields with CR and
  DR. See Section 15.3.3.8 for more information.

  You must use a trailing minus or the CR/DR formatting
  character to indicate a negative number in an asterisk-fill or
  floating dollar sign field.

  For fields with trailing minus signs, BASIC prints a minus
  sign after negative numbers as shown in Example 1, and a
  space after positive numbers as shown in Example 2.

  Example 1
  !Standard field
  PRINT USING "###.##",-10.54
  PRINT USING "###.##",10.54
  END

  Output 1
  -10.54
    10.54

  Example 2
  !Fields with Trailing Minus Signs
  PRINT USING "##.##-",-10.54
  PRINT USING "##.##-",10.54
  END

  Output 2
  10.54-
  10.54