8.2.3 No Pathological Implied-DO

The DO variable for an implied-DO construct in a DATA statement may not be used as the DO variable for an outer implied-DO construct. For example, this fragment is disallowed by g77:

DATA ((A(I, I), I= 1, 10), I= 1, 10) /.../

This also is disallowed by Fortran 90, as it offers no additional capabilities and would have a variety of possible meanings.

Note that it is very unlikely that any production Fortran code tries to use this unsupported construct.