1. A method of rendering an item set comprising items having a first sort order and a second sort order that is different from the first sort order as a selected list and an unselected list having an unselected list size limit on a computer having a processor and a display component, the method comprising: executing on the processor instructions configured to: to selected items of the item set, attach a selected marker; for unselected items of the item set: sort the unselected items according to the second sort order, and to the unselected items that, when the unselected items are sorted according to the second sort order, have a priority order index below the unselected list size limit, attach a hidden marker; store an item list persisting the selected markers attached to the selected items and the hidden markers attached to the unselected items; concurrently present: in a first region of the display component, the items of the item list having a selected marker sorted according to the first sort order; and in a second region of the display component that is different from the first region, the unselected list as the items of the item list having neither a selected marker nor a hidden marker and sorted according to the first sort order; and upon receiving a second request to present the selected list and the unselected list: retrieve the item list including the selected markers and the hidden markers; and concurrently present: in a first region of the display component, the items of the item list having a selected marker; and in a second region of the display component that is different from the first region, the unselected list as the items of the item list having neither a selected marker nor a hidden marker.