This example will demonstrate how you would setup a group of ranks for all users, based on post count. Administrators will get a special rank and will not have the rank that everyone else has.
Since we have set the Display Type of the All Usergroups ranks to Displaygroup, we have invoked the special setting mentioned in Modifying User Ranks. The All Usergroups ranks will display for everyone except for those in the Administrator group since that group has a rank explicitly defined, the ADMIN rank. Since we have set Stack Rank to No for both ranks, that means that the rank will appear all on one line.
Ranks are evaluated by usergroupid in reverse order. This means that the All Usergroups rank will appear last. If you wish to have ADMIN appear on one line, and the All Usergroups rank on another, you would set the Stack Rank option of the Administrator group to Yes. This will result in an html <br /> being placed after ADMIN. The All Usergroups rank would then follow, displaying on a new line.
The ADMIN rank would only display for users that had the Administrator group as their primary Usergroup or as a Secondary group. If the Display Type of the Administrator group's rank was changed to Displaygroup, then this rank would only show for those user's who have set the Administrator group as their displaygroup. That would be accomplished either by the user only being in the Administrator group, being a member of multiple groups assigned by the admin and having the Admin group as their displaygroup, or by having used Public Groups to to join the Admin group and choosing that as their display group.
The last scenario is quite unlikely since you would not allow members to join the Administrator group on their own choosing but the logic can be applied to other groups.