I am confused about the exact limitations on folder names in an ISO 9660 (Level 1) compliant filesystem. I read through the wikipedia page and it says:
File names are limited to eight characters with a three-character extension, using upper case letters, numbers and underscore only. - wikipedia
When it says 'File Names' does it really mean file or folder names? if not then what are the restrictions on folder names?
Thanks!
You can get the original ISO 9660 standard and its 1987 revision from Ecma International. The precise text is
10.1 Level 1
At Level 1 the following restrictions shall apply:
- Each file shall consist of only one File Section;
- a File Name shall not contain more than 8 [characters];
- a File Name Extension shall not contain more than 3 [characters];
- a Directory Identifier shall not contain more than 8 [characters].
(I've elided the distinction between "d-characters" and "d1-characters" which is irrelevant here.)
So the answer to your question is, at level 1, file names are restricted to 8+3 characters a la DOS, but directory ("folder") names are restricted to eight characters with no extension (unlike DOS, if I remember correctly).
Note that the standard has always included Level 2, which allows 31-character filenames (but still, if I'm reading it right, with only one dot); Level 1 is only for interop with pre-VFAT DOS, and shouldn't be necessary in a CDROM mastered today. (The restrictions on the size and depth of a CDROM directory hierarchy are, unfortunately, still relevant.)