Extras - or background actors, a politically correct term dictated by SAG-AFTRA - are of course the actors required to fill-out the background of a screen story. Without extras, the world of film and television would look as empty as a movie theater playing a double feature marathon of “Heaven’s Gate” and “Ishtar.”

Some actors use being an extra as their occupation to pay life’s bills, while pursuing acting through professional training and auditions elsewhere. Great! No problem there.

Some actors are full-time extras. This is their occupation. Year after year, full-time background actors are able to stitch together a living wage. They enjoy the on-set camaraderie. And they are content with the status of an extra. They have no delusions that their participation in our business as a background actor will propel them to above-the-title talent. Fine and dandy.

But then, there are the actors who have that extra smell.

Possibly you’ve encountered them on your journey. You may recognize these actors, who believe their stunning beauty or unusual look glimpsed on the screen for less than a nanosecond, will have a director or producer shout, “Get me that actor! That’s the star of my next budget-busting-blockbuster!” These extras are often deeply mired in conspiracy theories thinking Disney is gaining global domination via KFC buckets. They’re Glenn Becks without the chalkboard.

What further defines an actor with that extra smell?

1. If you have a plethora of credits on your resume that read like the following actual credit from an actor’s resume: “Professional business man on the park bench reading The Wall Street Journal as Jennifer Anniston jogged by,” you have that extra smell.

2. If when you open your closet, you refer to your wardrobe by project name such as, “For my date tonight, I think I’ll wear ‘The Lovely Bones.’ ” You have that extra smell.

3. If there’s an application on your smartphone listing of all the public bathrooms that can be used as a changing room while on location, you have that extra smell.

4. If you have more autographs of the principals you’ve “worked with” than principal credits on your resume, you have that extra smell.

5. If you have a composite card that displays you in various costumes from your roles as an extra and send that as a headshot to casting for principal work consideration, you have that extra smell.

6. If you send your picture and resume to a casting office that casts only principals and you ask to be considered for extra work, you have that extra smell.

7. If you were a non-union background actor on a union film (meaning SAG extras got seconds of screen-time while the audience saw the back of your head as a blip) and you list the credit on your resume as “featured,” you have that extra smell.

8. If you complain to the caterer at craft services that their tri-colored pasta salad has been deteriorating in quality over the past several years, you have that extra smell.

9. If you think the director happens to silently notice you, and he will instantly, without hearing you speak, catapult you to principal, you have that Extra smell.

10. If you find yourself gazing dreamily at a nearby honeywagon on set and fantasize it’s an oasis of stardom, you have that Extra smell.

11. If while dressed uniformly with your peer extras, you notice that your robe has a silver buckle upon its sash while the extra standing next to you has a sash with a gold buckle. And if this slight in lower metallic grade upon your costume causes you ire, you have that Extra smell.

12. If you go to set, as an extra, with a backpack bulging with screenplays you’ve written – for you to star in - and your sole intent for the day is to distribute them to anyone on set, you have that extra smell.

13. If you’re working on a James Cameron film, as an extra, and the closest you’ve gotten to Mr. Cameron is the third AD; but when speaking to fellow extras, you find yourself saying, “James thinks I would be fantastic for the president alien who stops the oil tanker from plowing into the Statue of Liberty,” you have that extra smell.

14. If you claim to have been a screen actor for more than twenty years, but while on set someone mentions Mali Finn and Mary Colquhoun and you respond with, “I caught their act in Vegas,” you have that extra smell.

15. If when watching a movie, that you did not participate in, you find yourself ignoring the principals and watching the extras to evaluate their performance, you have that extra smell.

16. If you’ve been lobbying SAG-AFTRA, The Academy of Motion Pictures & Sciences, and The Academy of Television Arts & Sciences that each implement an award category Best Extra in a Comedy, Drama or Musical, you have that extra smell.

Having that extra smell is being the delusional actor who foolishly believes that by being a repetitive extra, they’re preordained for the following: above the title billing, limousines, paparazzi, invites to Jay Leno’s couch, a sex scandal leading to drug rehab, and then a career rebirth as they’re welcomed back with a warm embrace by Oprah.

There’s nothing wrong with working as an extra, if the work is put into proper perspective by the participant. Look upon the experience as a paycheck and networking opportunity. If extra work is approached with self-fantasies of leading to your eventual fame, well, you have that Extra smell.

My talent representation, casting colleagues, and I continually advise actors who want to seriously pursue principal work on screen to minimize or delete all their extra credits from the resume sent to principal casting directors and legit talent agents.

Now, before some actors misinterpret that statement and post on an online message board misinformation stating, “Paul Russell said….” let me re-state more plainly. Take the paychecks. Remove or minimize the extra credits on your resume if you want to be considered for principal work on screen. Have a separate resume listing your history as an Extra for casting directors who cast background actors.

And what if extra credits are all an actor has listed under the Film/TV header of their resume and you want to grow beyond an extra? Minimize. Actors with that extra smell who want to be principals will often put every walk-on upon their resume. Which in turn leads the purveyor (casting directors and talent agents) of the actor’s work history to ponder, “Has a look but probably can’t act.” Or worse, “What mental deficiency within this actor is keeping directors from trusting him/her with an Under Five or better?”

There’s nothing disgraceful about being an extra (other than the sometimes disgraceful treatment of extras on set). Being an extra produces a paycheck. The work provides you new contacts. The temporary employ won’t be an end-solution for becoming a star. Which by-the-by, fame should never be the reason for being an actor, and if that is your sole intent for being in the arts, you have that extra smell.