I'm trying to create a bootable CD (3 unsuccessful tries till now), I think I got it now. I'm testing with syslinux first but I think it has a much tighter filename length limit.
Has anyone created one, I would like to know how long filenames I can use, the docs say that with ISO level 2 I should be able to get 31 chars, but I don't understand why syslinux has a different limit.
What you need to look for when researching on CD and long names are the Joliet and/or RockRidge extensions. From the syslinux documentation, isolinux uses plain iso9660 filenames, that means no extension filenames.
<added> Maybe you got the impression that by using syslinux every file on the disk should be length limited. That is not right; only isolinux will read still the short names, you can use any length allowed by rockridge or joliet by passing -R -J to mkisofs.