Recurring Cast refers to actors which are contracted to the show for limited number of episodes. Although their character may play an important role, they generally do not appear in every episode and their storylines tend to be related to their effect on the main characters. This option is also sometimes used for cast members who become part of the show after the intitial casting period and thus have more temporary contracts. Traditionally if a recurring cast member begins to appear is most episodes, they will later be promoted to Series Regular.