The .DISPLAY ELEMENTS command allows you to specify the form that
    sequential numbering or lettering of items in a list will take.
    This command does not change any values; it affects only the way
    the values are displayed. (See also .LIST, .END LIST, and .NUMBER
    LIST.)
    Format
      .DISPLAY ELEMENTS  ["x",] y [,"z"] (or ['x',] y [,'z'])
    Abreviated format
      .DLE  ["x",] y [,"z"] (or ['x',] y [,'z'])
1 – Parameters
 x
    A character, such as a left parenthesis or bracket, that you can
    specify to precede the number or letter. You must enclose the
    character in quotation marks (" ") or apostrophes (' ').
 y
    One of the following one- or two-letter codes:
    Code  Form of Sequence and Case
    D     Decimal numbers
    O     Octal numbers
    H     Hexadecimal numbers
    RU    Roman uppercase numerals
    RL    Roman lowercase numerals
    RM    Roman mixed case numerals - only first numeral is uppercase
    LU    Letters, uppercase
    LL    Letters, lowercase
    LM    Letters, mixed case - only first letter is uppercase
 z
    A character, such as a right parenthesis or bracket, that you
    can specify to follow the number or letter. You must enclose the
    character in quotation marks (" ") or apostrophes (' ').
2 – Default
A space for x, decimal numbers for y, and a period (.) for z