A shooting script is the version of a screenplay used during the production of a motion picture. Shooting scripts are distinct from spec scripts in that they make use of scene numbers (along with certain other formatting conventions described below), and they follow a well-defined set of procedures specifying how script revisions should be implemented and circulated. Overview When a screenplay is approved for production, the scenes are assigned numbers which are included in the script alongside the scene headers. The numbers provide a convenient way for the various production departments to reference individual scenes. Also each individual shot within a scene is also assigned numbers. After a shooting script has been widely circulated, page numbers are locked, and any revisions are distributed on revision pages. Thus the production office might issue a revision containing new pages 3, 9, 17 and 45. This avoids having to print and distribute an entirely new draft for every set of revisions, which would entail crew members having to transfer all their handwritten notes to a new script. If scenes on page 45 become longer, they will be continued on new pages 45A, 45B and so on; if the scenes on page 45 are all eliminated, a new page 45 will be issued with the word "OMITTED" as the absence of a page 45 might look like an error. Revision pages are distributed on colored paper, a different color for each set of revisions, with each changed line marked by an asterisk in the right margin of the page. The progression of colors varies from one production to the next, but a typical sequence would be: white, blue, pink, yellow, green, goldenrod, buff, salmon, cherry, tan, ivory, white (this time known as "double white"), and back to blue ("double blue"). When the assistant director believes that there are more changed pages than are worth swapping out, the script coordinator may issue an entirely fresh script in the appropriate revision color. In some cases, usually before the start of principal photography, an entirely new "white draft" will be distributed in lieu of colored revision pages. The pages in a white draft are renumbered from scratch, while the original scene numbers are maintained. Preserving scene and page numbers When revisions are made to a shooting script, they must be accomplished in a way that does not disturb the pre-existing scene numbers. Changes made to scene numbers