To store the maximum number of files on FAT file systems, such as PC Card storage devices, you should limit file names to eight uppercase characters and file extensions to three uppercase characters. File names that do not conform to these limits require more than one physical directory entry on a PC Card.
Windows CE does not allow the following characters in a file or directory name:
'*' , '\\', '/','?', '>', '<', ':', '"', '|', and any character whose value is less than 32.
Note that the OEM also might have specified characters that are not valid in file names.