This is a public list, visible in the members area. Admin are able to add a user to the group in the ACP using the forum and set a time when that members punishment will expire. I use it to place users in groups for discipline problems, such as quarantined to one hidden forum to post or have their bb code disabled with a photo share ban. The queue displays the members name, when they were placed in the group, what group they were placed in, when it will expire and why they were placed in the group.
I do not have to answer questions about when a user will have their posting privileges restored to normal and the add-on will automatically remove them from the group when the time expires that I selected for each member.