Unique identifier on each film frame—Kodak standard for digital and celluloid material management. EDLs and VFX coordination depend on it.
Each individual frame of your negative or positive material carries a unique number — this is the keycode. Kodak developed this standard, and it's printed directly onto the celluloid itself, outside the image area. In the digital workflow world, this functions identically: each digitized frame is automatically assigned the original keycode during scanning. This is not an arbitrary sequence of numbers — it actually encodes the reel, the position, and the exact context of the material.
On set, you don't need to worry about it, but in the edit, keycode becomes the basis of your coordination. When you're working in your NLE and need to hand off to grading, VFX, or archiving later, you write an EDL — Edit Decision List. This EDL only works cleanly if each frame is precisely identifiable by its keycode. Specifically, this means your editing decisions are tied to keycode, not to timecode or filename. A dailies proxy can be scaled or re-compressed arbitrarily — the keycode remains invariant.
In practice, you'll see keycodes in layer info panels or metadata views. The format is typically: Manufacturer (KJ for Kodak) – Reel Number – Frame Position. If your VFX supervisor returns a plate and says "Frame 147,500 has an error," you know immediately: this isn't timecode-dependent nonsense, but an unambiguously identifiable original material frame. This saves endless inquiries about potential pulldown errors or framerate mismatches.
Modern workflows integrate keycode automatically: it's logged in the DIT report, and in the conform session, you calculate the exact exposure or grading information for each cut via keycode. Even with digital cameras — where technically there's no "Kodak material" — manufacturers simulate a keycode-like index in the metadata header to maintain compatibility. This saves you from migrating to proprietary database systems. Keycode is the universal language between editing, grading, VFX, and archive — and it works so reliably because it doesn't rely on software, but rests on a physical or metadata-based reality.