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

  Dw.d
  (Exponential Editing)

  On input, performs the same as F format.

  On output, performs the same as E format, except that the letter D
  replaces the letter E preceding the exponent and the size of the
  exponent is fixed at 2.