The .CONTROL CHARACTERS command causes DSR to accept control
    characters as normal text in your input file. The characters
    that are affected by this command are the characters in the DEC
    Multinational character set with the following decimal values;
    1 to 31, 128 to 159, and 255. The control characters 0 (NULL)
    and 127 (DEL) can only be inserted into a document by using
    the accept flag (_). A form feed (Ctrl/L or ASCII 12) must be
    preceded by the accept flag if used in column 1.

    The .NO CONTROL CHARACTERS command does not accept control
    characters as normal text.

    Formats

      .CONTROL CHARACTERS

      .NO CONTROL CHARACTERS

    Abreviated formats

      .CC

      .NCC