This feature is available in Enterprise and Ultimate editions.
For some teams, using the priority value on requests is sufficient to organize and sort their list. Other teams might prefer to have specific control over the position of each request in the list. When in the default display settings, requests are displayed in their rank order. You can change the order of requests in your grid by:
Dragging and dropping requests up or down the ordered list
Clicking the up arrows to move a request up one spot or to the top of the page
Clicking a column heading to change the order from ascending to descending, or vice versa
You can use filters and customization to more quickly order a large number of requests. Absolute ordering is most important for items at the top of the list that are ready to be considered. The importance of an item's precise ordering is diminished the farther that item is down the list.
For ordering purposes, new requests are automatically appended to the end of the request list within a project.