The .FLAGS PERIOD and .NO FLAGS PERIOD commands turn on and turn
    off recognition of the Period flag character (+). When the period
    flag is in effect, an extra space is inserted after the following
    punctuation marks: period (.), colon (:), question mark (?) and
    exclamation point (!).
    Formats
      .FLAGS PERIOD  [k]
      .NO FLAGS PERIOD
    Abreviated formats
      .FL PERIOD  [k]
      .NFL PERIOD
1 – Parameter
 k
    Specifies a character to replace the current flag character.
2 – Default
    .PERIOD FLAG - Recognition of the Period flag character (+) is
    turned on.