BlackBerry 10 OS supports a variety of filesystems, each of which has different capabilities and rules for valid filenames.
For information about filesystem capabilities, see Working with Filesystems; for filesystem limits, see Understanding System Limits.
If you're using UTF-8 representations of Unicode characters to represent international characters, the limit on the filename length will be lower, depending on your use of characters in the extended range.
You can also use the ISO-Latin1 supplemental and PC character sets for international characters; however, the appearance of these 8-bit characters depends on the display settings of your terminal, and might not appear as you expect in other operating systems that access the files via a network.