Yeah, slashes in file names are bad news. Sometimes they’re OK but not always. It’s definitely bad practice in my book. You can still keep the slashes and special characters in the metadata and the CD-Text which has a limitation on special characters. According to Wikipedia:
The original Sony authoring tools and specifications supported ASCII and two of its supersets, ISO-8859-1 and “MS-JIS”.
Bottom line:
1) Metadata allows for lots of special characters.
2) CD-Text allows for some but not many special characters.
3) Keep any special characters or slashes out of the file names.
I can’t remember where but I think there is a setting that prevents rendered files from having illegal characters in the name, or maybe it’s automatic now. Before this setting, I once had a case where a file name had a question mark in it. I zipped the folder of files like usual and delivered it to the client as usual.
The client kept telling me that song 7 was missing and after some troubleshooting, I learned that if you zip a folder of files on a Mac, and a file has a special character such as a question mark, the file will vanish when unzipped on Windows.
Since then, I keep file names simple, and handle the special stuff in CD-Text/Metadata and life goes on.