The regular cast section is only for the main or starring cast of the series. It is reserved exclusively for cast members with a series regular status per a season on-screen credits.
Any actor not credited as a series regular—including but not limited to recurring guest stars, guest stars and co-stars—should be added as a Guest Star instead. These actors not credited as series regulars might appear in one, a few, half, most, or even every episodes of a season.
Preferably, only the series regulars who are in all or most episodes of a season should be added as season regulars. Series regular actors are generally credited in every episode of a season, but the characters might not appear in every episode. It is completely normal for regular cast members to be missing from one or a few episodes of a season (i.e. credit only). This is often the case with television series with large ensemble cast. However, if a series regular is only in half of a season, they can be added as a guest star instead.
The host is usually credited as a season regular for talk shows and game shows. The same is true for the narrator of a documentary series.
Before adding a new or missing regular cast member, always take the time to check previous contributions–are they already added as a guest star?–and do the necessary research to make sure they qualify.
Some series do not have season regulars. As an example, the anthology series Black Mirror does not have any series regulars because each episode has a different cast.
One important thing to remember is that each season is independent:
- The regular cast can change a little bit (e.g. Heroes), be completely different (e.g. Fargo) or stay exactly the same (e.g. Friends) from one season to the next .
- An actor can be guest starring or recurring for the first two seasons (Guest Star) and promoted as regular for season three (Regular Cast).
- An actor can be a series regular for the first six seasons (Regular Cast) and be a guest start in the seventh season (Guest Star).
The "Add To Every Season?" box should only be checked if an actor is a series regular for every (produced) season of the show.
When a series regular play two or more main roles (e.g. twins), they are usually credited as "Character 1 / Character 2". We sometimes choose not to credit a main role when the role itself is a big spoiler.
When series regular play different character each seasons, the characters should be credited individually. A good example is the horror anthology series American Horror Story.
When a series regular play a one episode role, they are not credited at all. For example, when a series regular play their character's parent in a flashback episode.