Design rule for Camera File system

These directories contain files with names such as "ABCD1234.JPG" that consist of four alphanumeric characters (often "100_", "DSC0", "DSCF", "IMG_", "MOV_", or "P000"), followed by a number in the range 0001...9999.

[citation needed] As an example of the DCF structure, the files on a Nikon D40 are arranged according to the above specification.

Images in this folder are named "DSC_xxxx", where xxxx represents the file's sequential number.

As this is an industry standard, similar directory structures and naming procedures can be found in most digital cameras.

The standard leaves room for varying types of file and directory organisations.

On the other hand, other manufacturers, such as Canon, Nikon and Sony, do usually not use numbering in the alphanumeric part of the filename.

Instead, Sony and Nikon tend to use "DSC_" for many camera models, while Canon opts to use "IMG_" for image based files, "MVI_" for video based files and "CSI_" for pictures taken in burst mode, thereby using the filename to indicate the type or the mode of photography used.

Consequently, if the prefix used is "DSC0", it may cause users who are not aware of the DCF standard to wonder why the picture counter wraps around after 9999, while there is seemingly still a significant number left.

DCF media is defined as removable memory recorded in compliance with the DCF specification or, removable and non-removable memory that a file system can access from an external device through IF (regardless of wired or wireless)[vague].