Davo is correct about an admin being able to add stamps. (In past QA Testing periods I have run the test for this more than once, so I know it can be done.) However, having to constantly switch between which stamp you want to use, will very quickly become an exercise in frustration. That's because each time you want to switch to, and use a different stamp, it takes a minimum of three clicks. One to open the menu of stamps, one to select the stamp to use, then another click in the annotation PDF to place the mark. What I tried doing just before retiring, was try to use a tablet with pen, and just draw. The pen and tablet makes a huge difference in quality and ease of use and getting what you want.