const j;
void main()
{
    int i = j;
}

You'll see that j is not declared an int (but it is one) nor has static or external linkage.

I don't know about the rest of you but I consider this very bad practice. Just as bad as using old K&R function declarations:

/* prototype */
foo();

/* implementation */
foo(x)
int x;
{
    return x;
}