RemoveSet - Remove all instances from collection (Ctrl+Del)

The remove set action will be activated for controls referring to not owning collections, only. When the data source is not a reference or relationship or when the collection does own its instances, the action is inactive (hidden) and cannot be called.

When list items are available read-only, the action will be disabled.

When calling the action, it will remove all listed instances without warning or message. In order to receive a warning message before deleting an instance the GUIFramework.Query.Delete option should be set (see "Option browser").

When a selection has been set for the list, items fulfilling the selection criteria (visible items) are removed, only.