I logged into xnat-dev05. That list should clean itself up over time. It shouldn't get indefinitely long. At the project level, I have it keeping track of the number of occurrences of workflow event IDs. It should only display the top 20, so as the site is fully utilized, workflows like the addition of specific users will work their way out. At the site level, the list is comprised of a unique set of all the top 20 from the projects, so the list can get longer than 20, but it will work its way down as the site is fully utilized. The one-off ones that include user names should work their way out as the site is fully utilized. That's what should be happening. At first look, it doesn't look like xnat-dev05 is utilized heavily enough (lots of projects, with relatively little activity on each) to cause the operations that include individual users to drop off. I thought about, but decided against hard-coded rules that would automatically try to lop off user names and such things. Looking at the workflows in HCP, there should be enough relatively standard ones that these shouldn't persist over time. I'd be happy to discuss further, if you see behavior different than I'm describing.