Welcome to utis.cc

This site is meant for hosting UTIs (Uniform Type Identifiers) that are not specific to one application or developer but shared among many apps, and therefore considered “open source”.

The domain utis.cc has been reserved for this purpose (currently paid until July 2026).

If you’re a developer and like to register a shared UTI, please contact us via the Issues tracker.

Currently known shared UTIs

• POSIX Paths File for storing and exchanging lists of file references.
• Pasteboard Types for clipboard tools (org.nspasteboard.TransientType, org.nspasteboard.ConcealedType, org.nspasteboard.AutoGeneratedType, org.nspasteboard.source).

Further resources on using UTIs

• Uniform Type Identifiers – Apple’s documentation on UTIs
• Uniform Type Identifiers — a reintroduction – a Tech Talk (video) clarifying a few things missing from the Apple docs
• Wikipedia article on UTIs

Some general information on declaring your own UTIs (file types)

A few things picked up from the aforementioned Tech Talk:

• All system-known UTIs are stored inside /System/Library/CoreServices/CoreTypes.bundle
• New regular file types should at least conform to “public.data”, or to “com.apple.package” if they’re a bundle directory.
• If you introduce a new document file type, one that the user would interact with, then add “public.content” to its conforming types.

Contact

Like to contribute?

Contact: tempelmann+utiscc@gmail.com
Twitter: @tempelorg