[stefantalpalaru]

It does not strike me as a sane design. You already have file extensions, unique prefixes (like those used by the 'file' command to identify files). Why would you use fs forks to differentiate between file types?

[ascorbic]

Mac OS Classic had no file extensions. I remember they felt like such a hack when switching to OS X, compared to the flexibility of resource forks.

[amyjess]

Actually, Classic Mac OS used type and creator codes, which were attributes on files, to identify filetypes, not resources.

[stefantalpalaru]

That makes more sense.