VMS Help FORTRAN, Format Specifiers, X  *Conan The Librarian (sorry for the slow response - running on an old VAX)

  nX (Skip Right n Positions)

  The X field descriptor functions the same as the TR field
  descriptor.

  On input, starts the next read operation after skipping "n"
  character positions.  If X is the last format item, it will have no
  effect.

  On output, starts the next write operation after skipping the "n"
  character positions.  Intervening characters are not written over.
  If X is the last format code executed, it will have no effect.

  The position specified must be an integer in the range 1 through
  the size of the record.