本规程规定了将电影从一种胶片尺寸复制到另一种胶片尺寸时使用的放大/缩小比，同时保持原始胶片的纵横比和构图。这种做法还规定了结果副本上可投影图像区域的尺寸，并给出了最终投影副本上产生不透明边框的蒙版的尺寸。还规定了相机取景器标记的尺寸，这些标记可用于复印格式的原始摄影。

This practice specifies the enlargement/reduction ratios to be used in copying motion pictures from one film size to another while maintaining the aspect ratio and composition of the original film.This practice also specifies the dimensions of the projectable image area on the resulting copy, and gives the dimensions for a matte which produces an opaque border on the final projection copy. Also specified are dimensions for camera viewfinder marks which can be used in composing the original photography for the copy format.