It doesn’t exist. But based on the comment about not accepting Navy HP, I assume it’s 3rd AE with a HP limitation somewhere between 2,000 and 10,000. But that doesn’t explain why there is not a similar limitation on all the others (except DDE). Conspicuously missing is also an iondication of what the propulsion modes for all of these are. It hardly helps anyone who is not among the “very few actually understand the progression…” (I’m not sure he does either, or even that there is a "progression: for any other than 3rd AE to CE via the hierarchy of “unlimited” endorsements.)