We used the Joliet file system as a guideline for maximum file name length, i.e. 128 characters. Joliet is “an extension to the ISO 9660 CD-ROM file format from Microsoft that supports Windows long file names starting with Windows 95. Joliet supports the original 8.3 naming convention for compatibility with DOS and Windows 3.1 and also supports the Unicode character set.”

I will be consulting the Joliet specifications for:

• File Name Length limitations
• Directory Tree Depth limitations
• Directory Name Format limitations

http://bmrc.berkeley.edu/people/chaffee/jolspec.html