An array element initializer in an implied-DO construct in a
DATA statement must contain at least one reference to the DO
variables of each outer implied-DO construct. For example,
this fragment is disallowed by g77:
DATA (A, I= 1, 1) /1./
This also is disallowed by Fortran 90, as FORTRAN 77's more permissive
requirements offer no additional capabilities.
However, g77 doesn't necessarily diagnose all cases
where this requirement is not met.
Note that it is very unlikely that any production Fortran code tries to use this unsupported construct.