Public instance

Introduced with Update 14, public instances allow "open" parties where other players may join/leave at will without needing to apply to join the party first. These "public" parties can even be set to have no specified leader. Public parties are called out in the LFM, and can also be disabled from displaying. Any Public parties will display the current amount of time the quest has been active by the existing party members to provide better guidance of how far along the quest may be.