This question has been answered by multiple community members. See the first response.
http://yoursite.com/manager/?a=system/action

What version of MODX are you using? I should have mentioned that the values I gave are from V. 2.4.4.
B.t.w. I'm deeply pissed off by the permissions part, took me a week so far to set up a simple role of editors who can do what they need and not see what they need not. Hopefully, I can pay something back to this helpfull community as soon as I'm through with it.

In case you haven't seen it, here's a video of me explaining how the permission system actually works. It's about 50 minutes, but it might save you more time than that down the road.
https://vimeo.com/54360208