short version: DT has 'depths,' which by default, is set to 2, although it is possible to see up to 4. Depth 1 is managed directly by the administration; only the admins can add or remove uses from this category. Depth 2 is managed by the individuals in depth 1 by adding or excluding them to their trust lists (the big text box on this page
https://bitcointalk.org/index.php?action=trust).
when a dt1 user decides to add a user to their trust list, that user becomes a part of dt2, and vice versa for depths 3 and 4 as well (although depths 3 and 4 are nearly irrelevant ). At this point, for a person to be removed from their dt2 position, 1 of 2 things can happen;
1. the dt1 member who added that user to their trust list removes them
2. the user is
excluded by at least 2 other members in dt1 by entering ~<username> as opposed to just their username into the list
the second method serves to ensure that dt2 can be self - monitored to an extent without direct interference by the administration. If a member is taken off of dt2 through exclusion, their name will be 'slashed through' on the trust settings page as such:
username.
Also, if you're wondering what the numbers next to their names mean, it denotes the number of dt1 users that have decided to either add or exclude a member from their trust lists. assuming the user is on 1 dt1 user's trust list (1), the exclusion of the member by 2 other users would put them at a (-1).
If you're curious, you can click the 'hierarchical view' link at the bottom of the page, and you will be able to see exactly which users have decided to include or exclude certain users from their trust lists.
In this case, it would seem Lauda has been excluded by 3 dt1 members: HostFat, OgNasty, and Tomatocage, while he is on the trust lists of 2 members: Blazed and hilariousandco.
