Formatting Question: Repeated scene in Flashback

I'm not sure if there's a standard for the particular situation you're referring to - there very well might be - but if it was me, I'd make it as clear as possible and use both notations. (Flashback to ep.3 scene 12 in the slugline, or at least the episode if the scenes aren't numbered, and copy/paste the (part of the) scene - because I assume the flashback won't always be an entire scene.)

That way it's clear that this is a flashback to something which has already been filmed in a previous episode and it doesn't have to be filmed again, but the reader doesn't have to go dig up that old script to be able to follow the storyline either.

This also seems like one of those situations where it's perfectly acceptable to double check with whoever you work for (a showrunner perhaps?), to make sure you're all on the same page and there's no confusion possible.

I would handle it simply as action:

Her mind flashes back to (brief description of incident).

Or, Horror crosses his face as he remembers, etc.

I wouldn't slug it as a 'mental' image, since the only way to SHOW a memory - is to slug it. That's industry standard.

You can LEAD to the slug with a physical REACTION to the memory.

Joan recoils in horror as - FLASHBACK

INT: HOTEL ROOM - NIGHT - EPISODE 3 SCENE 7

Cut and paste the scene.

RETURN TO PRESENT

INT: CAR - DAY

Bob looks at Joan in her catatonic state.

BOB
Joan? Are you okay?


As other's have said - you should check with the head writer or show runner. Television show series have their own quirks to their format. If you can get hold of a previous script - that's best. It will illustrate their approach.

I'd cut and paste if you are using THE EXACT SAME FOOTAGE that was utilized in the earlier episode.

HOWEVER

You might be using the same scene, but from a different POV. Perhaps in the earlier episode, we saw Joan being kidnapped and tortured. In THIS episode, we see the scene from JOANS EYES. In other words, it's a different POV - different camera angles. Perhaps even more information is revealed. While you are techinically flashing back to an earlier event in the story line - it's going to require use of different footage.

Joan recoils in horror as - FLASHBACK

INT: HOTEL ROOM - NIGHT

Joan is tied to the chair, held captive by the bad guys. Tears soak her blind fold. She tilts her head back, and manages a peek beneath the edge of the silk band. She spots.... the BLUE SUEDE SHOES of her torturer.

RETURN TO PRESENT

Etc...

In that case, while we are returning to the scene of the crime - literally - we are seeing something new, learning new information - experiencing it from a new point of view. So FLASHBACK is used - THE SAME HEADING that is used to slug it in the earlier script - but new information/dialog is provided.

That's my take on it.