The .LIST command specifies the beginning of a list by resetting
    the left margin farther to the right, by setting a .SKIP command
    value to take effect before each item in the list, and by
    executing .TEST PAGE. Use the .LIST ELEMENT command to specify
    each item in the list. .LIST ELEMENT commands also give you
    numbers or letters in sequence in the left margin or let you
    substitute a single character of your choice for each of the
    numbers or letters (for example, the lowercase letter o, which
    is known as a "bullet"). (See also .DISPLAY ELEMENTS and .NUMBER
    LIST.)

    The .END LIST command ends a list, restoring any fill, justify,
    case, margin, or spacing settings that were in effect before you
    entered the most recent .LIST command. You can also specify a
    value with .END LIST that puts blank lines after the last item in
    the list (as with .SKIP).

    Formats

      .LIST  [[-]n] ["x"]

      .END LIST  [[-]n]

      .LIST  [[-]n] ['x']

      .END LIST  [[-]n]

    Abreviated formats

      .LS  [[-]n] ["x"]

      .ELS  [[-]n]

      .LS  [[-]n] ['x']

      .ELS  [[-]n]