Keykode (also written as KeyKode or KeyCode ) is an Eastman Kodak Company advancement on edge numbers , which are letters, numbers and symbols placed at regular intervals along the edge of 35mm and 16mm film to allow for frame-by-frame specific identification. It was introduced in 1990.
Keykode is a variation of time code used in the post-production process which is designed to uniquely identify film frames in a film stock .
Edge numbers (also known as numbers numbers or footage numbers) are a series of 16-bit negatives (16 frames or 64 perforations) and 16 mm negative at intervals of six inches (twenty frames). The numbers are placed on the negative side of one of two methods:
- Latent image exposes the edge of the movie while it passes through the punching machine. This method is primarily used for color negative films.
- Visible ink is sometimes used to imprint on the edge of the film – again in manufacturing – at the time of perforations. The ink, which is not affected by photographic chemicals, is normally printed on the base surface of the film. The numbers are visible on both raw (unexposed) and processed (exposed and developed) film. This method is used for black & white negative film.
The edge numbers serve a number of purposes. Every key frame is numbered with a multi-digit identifier that may be referred to later. In addition, a date of manufacturing is imprinted, then the type of emulsion and the batch number. This information is available from the negative (visible to visible developed) to the positive prints. The print can be edited and handled while the original negative remains safely untouched. When the film editing is complete, the edge numbers on the final cut movie is back to their original style.
Laboratories can also imprint their own numbers on the film negative or print to identify the film for their own means. This is normally done in yellow ink. A common workflow for film editing involves simultaneous film-synchronization with the film’s synchronized audio track, which has a 35mm magnetic film , so that a foot of film and its synchronized audio have identical edge numbers.
Eastman Kodak began using latent image edge numbering on their manufactured 35mm raw film stocks in 1919.  
With the popularity of telecine transfers and video edits, Kodak invented a machine readable edge number that could be recorded via computer, read by the editing computer and automatically produce a “cut list” from the video edit of the film.
To do this, Kodak uses the USS-128 barcode alongside the human-readable edge numbers. They also improve the quality and readability of the human-readable information to make it easier to identify. The Keykode consists of 12 characters in human-readable form followed by the same information in barcode form. Keykode is a form of metadata identifier for negative film.
An example Keykode:
KU 22 9611 1802 + 02.3
- The first two letters in the Keycode are the manufacturer code (
Kboth stand for Kodak ,
Fstands for Fuji , etc.) and the stock identifier, respectively (in this case Kodak’s
Ustanding for 5279 emulsion); each manufacturer has different stocks’ naming convention for their emulsion codes.
- The next six numbers in the Keykode (usually split in 2 + 4 digits) are the identification number for that roll of film. On Kodak film stocks, it remains consistent for the entire roll. Fuji Stocks will be increment this number when the frame number advances “9999”.
- Computers read the (optional) frame offset (marked every four perforations on a movie by a single “-” dash) by adding digits to the Keykode after the plus sign. In this case, a frame offset of two frames (with respect to the movie foot) is specified. The number of frames Within a football movie depends on Both the movie and the frame width pulldown Itself, and can be aussi uneven dans le même roll, purpose Rather Periodically repeat (like in the 35mm 3perf. Pulldown).
- The last (optional), dot-separated number is the perforation offset which, if preceded by a frame offset like in the above example, is a bias within the just-specified frame; otherwise (as I understand by most DI software)
EASTMAN 5279 167 3301 122 KD
- These numbers are consistent for a whole batch of film and may not change in many rolls. EASTMAN is the film manufacturer, 5279 is the stock type identifier. The next three numbers (167) is the batch number emulsion. The next series of four digits (3301) is the roll and part code, followed by the identification number that makes the Keykode (122) and finally has two letter date designation (KD). In this case, KD = 1997.
- 35 mm film
- Color motion picture movie
- Stock film
- List of motion picture film stocks
- Basic film
- Time code
- Kodak Motion Picture Movie (H1) (4th ed). Eastman Kodak Company. ISBN 0-87985-477-4
- The Kodak Worldwide Student Student Program Filmmaker’s Handbook: Motion Picture and Television Imaging (H-19) (1991) (2nd Ed). Eastman Kodak Company.
- Konigsberg, Ira (1987). The Complete Dictionary Dictionary Meridan PAL books. ISBN 0-452-00980-4 .