JEITA CP-3451 - 28 - UserComment A tag for Exif users to write keywords or comments on the image besides those in ImageDescription, and without the character code limitations of the ImageDescription tag.   Tag = 37510 (9286.H) Type = UNDEFINED Count = Any Default = none The character code used in the UserComment tag is identified based on an ID code in a fixed 8-byte area at the start of the tag data area. The unused portion of the area is padded with NULL ("00.H"). ID codes are assigned by means of registration. The designation method and references for each character code are given in Table 6 . The value of Count N is determined based on the 8 bytes in the character code area and the number of bytes in the user comment part. Since the TYPE is not ASCII, NULL termination is not necessary (see Figure 9). Table 6 Character Codes and their Designation Character Code Code Designation (8 Bytes) References ASCII 41.H, 53.H, 43.H, 49.H, 49.H, 00.H, 00.H, 00.H ITU-T T.50 IA5 JIS 4A.H, 49.H, 53.H, 00.H, 00.H, 00.H, 00.H, 00.H JIS X208-1990 Unicode 55.H, 4E.H, 49.H, 43.H, 4F.H, 44.H, 45.H, 00.H Unicode Standard Undefined 00.H, 00.H, 00.H, 00.H, 00.H, 00.H, 00.H, 00.H Undefined Figure 9    User Comment Tag The ID code for the UserComment area may be a Defined code such as JIS or ASCII, or may be Undefined. The Undefined name is UndefinedText, and the ID code is filled with 8 bytes of all "NULL" ("00.H"). An Exif reader that reads the UserComment tag shall have a function for determining the ID code. This function is not required in Exif readers that do not use the    UserComment tag (see Table 7). ExifVersion …….. …….. Exif Private Tag Exif IFD Value of Exif IFD Character Code (8 Byte) …….. User Comment Column …….. UserComment