-61-DCF standardThe DCF specification imposes the following conditions.Limits on directory namesDirectories must be created within the main DCIM directory.• Data which is contained within any directory other than the DCIMdirectory cannot be recognised.Directory names must consist of three numerals (directorynumber) followed by five alphanumeric characters. (Example:100abcde)• The three numerals must make up a number between 100 and 999, andthe alphanumeric characters can be taken from the following set of 37characters: 0123456789abcdefghijklmnopqrstuvwxyz_ (No distinction ismade between upper-case and lower-case alphabetic characters.Double-byte characters cannot be used.)Multiple directories using the same three-digit combination(directory number) cannot be created.Directory sub-hierarchies are not supported.File namesFile names must consist of four alphanumeric charactersfollowed by four numerals (file number), followed by “.jpg”.(Example: abcd0001.jpg)• The four numerals must make up a number between 0001 and 9999, andthe alphanumeric characters can be taken from the following set of 37characters: 0123456789abcdefghijklmnopqrstuvwxyz_ (No distinction ismade between upper-case and lower-case alphabetic characters.Double-byte characters cannot be used.)Multiple file names using the same four-digit combination (filenumber) cannot be created.File formatOnly JPEG image files which comply with the Exif 2.1 standardare recognized.