In a format specification, the dollar sign ($) and backslash (\)
  characters modify the carriage control specified by the first
  character of the record.  They only affect carriage control for
  formatted files, and have no effect on input.

  If the first character of the record is a blank or a plus sign (+)
  the dollar sign and backslash descriptors suppress carriage return
  (after printing the record).

  For terminal device I/O, when this trailing carriage return is
  suppressed, a response follows output on the same line.

  If the first character of the record is 0, 1, or ASCII NUL, the
  dollar sign and backslash descriptors have no effect.