g77 treats double-quote (")
as beginning an octal constant of INTEGER(KIND=1) type
when the -fvxt option is specified.
The form of this octal constant is
"octal-digits
where octal-digits is a nonempty string of characters in
the set 01234567.
For example, the -fvxt option permits this:
PRINT *, "20
END
The above program would print the value 16.
See Integer Type, for information on the preferred construct for integer constants specified using GNU Fortran's octal notation.
(In the GNU Fortran language, the double-quote character (")
delimits a character constant just as does apostrophe (').
There is no way to allow
both constructs in the general case, since statements like
PRINT *,"2000 !comment?" would be ambiguous.)