VMS Help FORTRAN, Compatibility Features, Bit Constant Syntax  *Conan The Librarian (sorry for the slow response - running on an old VAX)

  In Compaq Fortran, you can use the following alternative syntax for
  binary, octal, and hexadecimal constants:

                  Alternative Syntax   Equivalent
                  ------------------   ----------
     Binary       B'0..1'              '0..1'B
     Octal        O'0..7'              '0..7'O
     Hexadecimal  X'0..F' or Z'0..F'   '0..F'X or '0..F'Z