Section 7,5: Octal_Notation

 Octal forms of integer constants allow compatibility with PDP-11
 FORTRAN.  You must specify the -vms compiler option to use octal
 notation.  Statement format:

    "nn

    nn  Is a string of digits in the range 0 to 7 (for
        example "107).

 Integer constants in octal form have integer data type and are
 treated as integers.